Answer: = a = 0.0206
b = 0.0205.
Step-by-step explanation:
From the question, given that;
Order Accurate = 328 273 242 142
Order Not Accurate = 32 54 37 20
Let us make the Total orders given be
T.O = 328+273+242+142+32+54+37+20 = 1128.
a) Let the Prob. that the first order is from restaurant D be
= Number of order from restaurant D / Total number of orders
= 162 / 1128 = 0.1436
Probability of the second order is 0.1436.
This is because, from the question we can tell that the selections are made with replacement, that means the order is the same.
So, the probability of getting 2 orders =
= 0.1436 * 0.1436 = 0.0206
NB: The probability of getting two orders from restaurant B is 0.0206.
This is because choosing the first order does not affect the second order
(independent events).
b) Assuming that the selections are made without replacement , the probability of getting both the orders from restaurant D =
Probability of getting 1st order from restaurant D = 162/1128 = 0.1436.Probability of getting 2nd order from restaurant D = 161 / 1127 = 0.1428This gives the Total Probability of getting both the orders from restaurant D, without replacement to be = 0.1436*0.1428
= 0.0205.
That is to say choosing the first order affects the second order because of the events are not independent as compared to the first question.
cheers i hope tis helps
One ingot contains 10 kg of pure silver and 2 kg of league. What quantity of silver, whose grade is 0.700; is it necessary to melt to obtain silver with a grade of 0.750?
a) 20
b) 22
c) 16
d) 24
e) 19
Answer:
a) 20
Step-by-step explanation:
If x is the kg of 0.700 grade silver, then:
Silver in ingot + silver in 0.700 alloy = silver in 0.750 alloy
10 + 0.7x = 0.75(x + 12)
10 + 0.7x = 0.75x + 9
1 = 0.05x
x = 20
A clothing business finds there is a linear relationship between the number of shirts, n, it can sell and the price, p, it can charge per shirt. In particular, historical data shows that 1,000 shirts can be sold at a price of $30, while 3,000 shirts can be sold at a price of $10. Find a linear equation in the form p(n)=mn+b that gives the price p they can charge for n shirts.
Answer:
p(n) = -1/100 n 40
Step-by-step explanation:
Use the two points (n, p): (1000, 30) and (3000, 10).
Now we find the equation of the line that passes through these two points.
m = (10 - 30)/(3000 - 1000)
m = -20/2000
m = -1/100
p(n) = mn + b
30 = -1/100 * 1000 + b
30 = -10 + b
b = 40
The equation is:
p(n) = -1/100 n 40
find the product 538 x 100=
Answer:
Answer=53,800
Step-by-step explanation:
just add the two zero behind the number
!2,19,26 what comes nxt
Answer:
12 , 19 , 26 , 33
Explaination:Here, n+7
12+7=19
19+7=26
So,
26+7=33
Hope you understand ❣
Step-by-step explanation:
12 , 19 , 26 , ?
Given
___________
a1= 12
a2= 19
a3 = 26
d= ?
a4 = ?
––——————
we can solve this by using formula from Ap .
But for this we have to find d
As we know that
common difference(d) = a2-a1 = 19 -12
= 7
so difference after every no is 7 so
a4 = a3 + d
= 26 +7
= 33
So 33 is ur answer mate
Hope it helps
Two sides of a triangle are equal length. The length of the third side exceeds the length of one of the other sides by 3 centimeters. The perimeter of the triangle is 93 centimeters. Find the length of each of the shorter sides of the triangle
Answer:
30 cm
Step-by-step explanation:
let x be the lenght of the two sides of equal lenghts, so the other is x+3
and the perimeter is x+x +x +3
P=3x+3
P=3(x+1)
93=3(x+1)
31=x+1
x=30
so the shorter sides are of 30 centimeters and the longest is 33
What kinds of people actually read printed information on the packaging before purchasing a product? As part of a larger study on the influence of product packaging on purchase decisions, a survey of 250 citizens of Sarajevo asked if they observed printed information before purchasing a product (Poturak, 2014). Assume that the sample was a simple random one.
Complete Question
The complete question is shown on the first uploaded image
Answer:
[tex]X = 1.2857[/tex]
Step-by-step explanation:
Generally from the table the contribution to the chi-square statistic of the number of individuals in the survey aged 20 - 22 who strongly disagreed about whether they observe packing information before purchasing items is mathematically represented as
[tex]X = \frac{(10 - 7)^2 }{7}[/tex]
[tex]X = 1.2857[/tex]
Determine what type of decimal each is.
8.54
●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●
Hi my lil bunny!
❧⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯☙
[tex]8.54 \div 100 = 0.0854[/tex]
(what do you mean by Determine what type of decimal each is: 8.54 because there is only one decimal there )
❧⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯☙
●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●
Have a great day/night!
❀*May*❀
Need Assitance
*Show Work*
Answer:
66 2/3 %
Step-by-step explanation:
First find the students not in the 8th grade
24 - 8 = 16
16 students are not in the 8th grade
Take the fraction of the students not in the 8th grade over the total
16/24 = 2/3
Change to a decimal
.66666666666
Multiply by 100 to change to a percent
66.666666%
66 2/3 %
Answer:
66.67% of students are not in eighth grade
Step-by-step explanation:
8/24=1/3
1/3=0.33333333333
1-0.33333333333=0.66666666667
0.66666666667=66.67%
When conducting a residual analysis, which plot would you look at to determine if the equal variance assumption is satisfied?
a. Scatter plot of Yhat vs. QN X
b. Scatter Plot of Residuals vs QN X
c. Scatter Plot of Residuals vs Yhat
d. Stem-and-Leaf Plot of the Zresiduals
Answer:
C.Scatter Plot of Residuals vs Yhat
Step-by-step explanation:
You make 85,000 per year and your company matches 50 cents for every dollar you deposit into your 401k plan, up to 8% of your salary.
Answer:
The question is incomplete, below is a possible match for the complete question:
You make $85,000 per year and your company matches 50 cents for every dollar you deposit into your 401k plan, up to 8% of your salary. Complete parts (a) through (c) below.
(a) If you contribute $200 every month to your 401k, what will your company contribute each month?
The company will contribute $ (Type an integer or a decimal rounded to two decimal places as needed.)
(b) If you contribute $830 every month to your 401k, what will your company contribute each month?
The company will contribute $ (Type an integer or a decimal rounded to two decimal places as needed.)
(c) What is the maximum amount of money the company will contribute to your 401k each year?
The maximum amount that the company will contribute each year is $
(Type an integer or a decimal rounded to two decimal places as needed.)
Answer:
a.) The company will contribute $100
b.) The company will contribute $415
c.) maximum amount the company will be willing to contribute = $6,800 per year
Step-by-step explanation:
First, let us calculate the maximum amount the company will be willing to pay into the 401k plan yearly:
Annual salary = $85,000
Monthly salary = $7083.3333
maximum amount = 8% = 8/100 = 0.08 of salary
maximum amount = 0.08 × 7083.3333 = $566.67
a.) If you contribute $200 every month.
Since $200 is less than the maximum amount that the company will be willing to contribute, let us calculate how much the company is willing to contribute:
Company matches 50 cents for every dollar you deposit
1 dollar deposited = 50 cents from company
but 1 cent = $0.01
∴ 50 cents = 0.01 × 50 = $0.5
$1 deposited = $0.5 from company
∴ $200 deposited = 0.5 × 200 = $100 contributed by company
Therefore, if you contribute $200 every month, your company will contribute $100 each month.
from this example, we can see that the company is willing to contribute half of every amount you deposit every month ($100 = half of $200), hence, subsequently, we will use this for calculations.
b.) If you contribute $830 every month, the company will be willing to contribute half this amount, which is:
half of $830 = 830 ÷ 2 = $415
Therefore, if you contribute $830 per month, your company will contribute $415 per month.
c.) The maximum amount the company will be willing to contribute each year = 8% of salary per year
= [tex]= \frac{8}{100}\times 85,000 \\ =0.08\ \times\ 85,000 = \$6,800[/tex]
Therefore, the company will be willing to contribute $6,800 per year.
An agriculture company is testing a new product that is designed to make plants grow taller. This can be thought of as a hypothesis test with the following hypotheses. H0: The product does not change the height of the plant. Ha: The product makes the plant grow taller. Is the following an example of a type I or type II error? The sample suggests that the product makes the plant grow taller, but it actually does not change the height of the plant.
Answer:
hi
Step-by-step explanation:
hji
g If the events A and B are independent with P( A) = 0.35 and P( B) = 0.45, then the probability that both events will occur simultaneously is:
Answer:
0.1575.
Step-by-step explanation:
Here, as they are independent, we multiply the probabilities:
P( A and B) = 0.35*0.45
= 0.1575.
The probability that both events will occur simultaneously is 0.1575.
Given that, the events A and B are independent with P( A) = 0.35 and P( B) = 0.45.
What is independent probability?Two events are independent if the occurrence of one event does not affect the chances of the occurrence of the other event. The mathematical formulation of the independence of events A and B is the probability of the occurrence of both A and B being equal to the product of the probabilities of A and B (i.e., P(A and B).
Since, the events A and B are independent
We have P(A and B)
= P(A) × P(B)
= 0.35 × 0.45
= 0.1575
Hence, the probability that both events will occur simultaneously is 0.1575.
Learn more about the independent probability here:
https://brainly.com/question/27987662.
#SPJ5
Question
Consider these functions.
f(x) = -9x + 14
g(x)=-3x2
Select the correct answer from each drop-down menu.i
If x = 6, then f(6)
If g(x) -48, then x =
and x =
Submit
Answer:
[tex]\large \boxed{-40, \ 4, \ -4}[/tex]
Step-by-step explanation:
[tex]f(x)=-9x+14[/tex]
[tex]\sf Put \ x \ as \ 6.[/tex]
[tex]f(6)=-9(6)+14[/tex]
[tex]f(6)=-54+14[/tex]
[tex]f(6)=-40[/tex]
[tex]g(x)=-3x^2[/tex]
[tex]\sf Put \ g(x) \ as \ -48.[/tex]
[tex]-48=-3x^2[/tex]
[tex]\displaystyle \frac{-48}{-3} =\frac{-3x^2 }{-3}[/tex]
[tex]16=x^2[/tex]
[tex]\sqrt{16} =\sqrt{x^2 }[/tex]
[tex]x= \pm 4[/tex]
Answer:
F(6) = -9(6) + 14 = -54 + 14. f(6) = -40
G(x) = -48 / g(x) = -3(16) / g(4) = -48
Step-by-step explanation:
For the first one the drop answer is -40
For the second one its 4 then 16
I think because that whats im seeing but these are the right answers :)
Suppose that the Blood Alcohol Content (BAC) of students who drink five beers varies from student to student according to a Normal distribution with mean 0.07 ans standard deviation 0.01.
1. The middle 95% of students who drink five beers have a BAC between
a. 0.06 and 0.08 b. 0.05 and 0.09 c. 0.04 and 0.10 d. 0.03 and 0.11
2. What percent of students who drink five beers have a BAC above 0.08 (the legal limit for driving in most states)?
a. 0.15% b. 0.3% c. 2.5% d. 16% e. 32%
3. What percent of students who drink five beers have a BAC above 0.10 (the legal limit for driving in most states)?
a. 0.15% b. 0.3% c. 2.5% d. 16% e. 32%
Answer:
1. b. 0.05 and 0.09
2. d. 16%
3. a. 0.15%
Step-by-step explanation:
Given that :
mean = 0.07
standard deviation = 0.01
Confidence interval = 95%
The level of significance ∝= 1 - 0.95 = 0.05
At 0.05 level of significance,
critical value for [tex]z_{\alpha/2} = z_{0.05/2}[/tex]
critical value for [tex]z_{0.025}[/tex] = 1.96
Confidence interval = [tex]\mathtt{\mu \pm ( {z} \times{\sigma})}[/tex]
Lower limit = [tex]\mathtt{\mu -( {z} \times{\sigma})}[/tex]
Upper Limit = [tex]\mathtt{\mu +( {z} \times{\sigma})}[/tex]
Lower limit = [tex]\mathtt{0.07 - ({1.96} \times {0.01})}[/tex]
Upper limit = [tex]\mathtt{0.07 + ({1.96} \times {0.01})}[/tex]
Lower limit = 0.07 - 0.0196
Upper limit = 0.07 + 0.0196
Lower limit = 0.0504 [tex]\simeq[/tex] 0.05
Upper limit = 0.0896 [tex]\simeq[/tex] 0.09
The confidence interval of 95% is ( 0.05, 0.09)
2. What percent of students who drink five beers have a BAC above 0.08 (the legal limit for driving in most states)?
[tex]P(X> 0.08) = P(\dfrac{0.08 - \mu}{\sigma} > \dfrac{X - \mu}{\sigma} )[/tex]
[tex]P(X > 0.08) = P(z > \dfrac{0.08 - 0.07}{0.01} )[/tex]
[tex]P(X > 0.08) = P(z > \dfrac{0.01}{0.01} )[/tex]
[tex]P(X > 0.08) = P(z > 1 )[/tex]
[tex]P(X> 0.08) = 1- P(z < 1 )[/tex]
P(X > 0.08) = 1 - 0.8413
P(X > 0.08) = 0.1587
P(X > 0.08) [tex]\simeq[/tex] 16%
3. What percent of students who drink five beers have a BAC above 0.10 (the legal limit for driving in most states)?
[tex]P(X> 0.10) = P(\dfrac{0.10 - \mu}{\sigma} > \dfrac{X - \mu}{\sigma} )[/tex]
[tex]P(X > 0.10) = P(z > \dfrac{0.10 - 0.07}{0.01} )[/tex]
[tex]P(X > 0.10) = P(z > \dfrac{0.03}{0.01} )[/tex]
[tex]P(X > 0.10) = P(z > 3)[/tex]
[tex]P(X> 0.10) = 1- P(z < 3 )[/tex]
P(X > 0.10) = 1 - 0.9987
P(X > 0.08) = 0.0013
P(X > 0.08) [tex]\simeq[/tex] 0.15% which is the closet value to 0.0013
What is the simplest fraction whose value is equal to the number (red heart) depicted on this number line. (Give your answer as a fraction, not a mixed number. "Simplest fraction" means the numerator and denominator should have no common divisor greater than 1. : Look closely at the numbers on the number line. (red heart) is between 2 and 3. There are 6 tick marks between 2 and 3. How many regions do those tick marks split the number line into?
Answer:
simplest fraction: 2 1/3 the tick marks split the number into 7 regions
Step-by-step explanation:
The red heart is on the 2 tick mark of the 6 ticks between 2 and 3. The answer is 2 2/6 which after simplifying if equal to 2 1/3.
Answer:
16/7
Step-by-step explanation:
2-3 is devided into 7 segments if you make 2 14/7 and 3 21/7 then you have 16/7 with no common devisor other than 1
In the diagram, XY bisects ZWXZ.
Z
Y
2
w
(5x + 3)
(7X - 70°
Х
x=
type your answer...
Answer:
x = 5
Step-by-step explanation:
Angle Bisector Theorem: When a ray bisects an angle, we get 2 congruent smaller angles
Step 1: Set equation equal to each other (Angle Bisector Theorem)
5x + 3 = 7x - 7
Step 2: Subtract 5x on both sides
3 = 2x - 7
Step 3: Isolate x term (Add 7 to both sides)
10 = 2x
Step 4: Isolate x (Divide both sides by 2)
x = 5
If a faucet drips 2ml of water every second, how much water will it spill waste in 2 days?
Answer:
[tex]\boxed{345,600 mL}[/tex]
Step-by-step explanation:
Hey there!
Well first we need to find the amount of seconds in a day,
24hrs in a day * 60 min in an hour
= 1440 minutes in a day
1440 min • 60 secs in a minute
= 86,400 seconds in a day
So now we do 2*86400 = 172800
172800 mL in a day
172800 * 2
= 345600 mL in 2 days
Hope this helps :)
Lennox owns a big apple orchard. She ships her apples to various markets using a fleet of trucks. Every week, each truck goes on 3 trips, and for each trip Lennox gets 300 dollars. On a single trip, a truck delivers 50 packs, and each pack contains 12 kilograms of apples. Overall, Lennox sells 4500 dollars worth of apples in a week. How much does Lennox get for a single kilogram of apples?
Answer:
$0.50
Step-by-step explanation:
Each trip transports 50 packs at 12 kg each, for a total of 600 kg. That trip nets $300 in income.
Lennox gets paid ($300)/(600 kg) = $0.50/kg, or 50¢ for 1 kg of apples
Answer:5 trucks
Step-by-step explanation: in kahn it’s 4500 divided by 900 because she makes 300 a trip which makes 900$ a truck
A study collects samples of water from the tap in Vacaville and from bottled water available from the Nugget stores and samples their pH levels. The results are in the table below. I find a bottle marked #13 but cannot read the label for the type of water. He measures the pH and gets 6.32. What type of water do you think it is?
Answer:
see below
Step-by-step explanation:
the observed ph is 6.32
the mean pH of Tap water is shown below
sum of observations
Mean (Tap) = -----------------------------------
number of observations
(7.24 +7.05 +7.07 +6.6 +7.28 +7.29 +7.05 +6.7 +7.16 +7.07 +7.12 +6.56
= ---------------------------------------------------------------------------------------------------------
12
= 7.016
then mean pH of bottle water is shown below
sum of observations
Mean (Bottles) = -----------------------------------
number of observations
(5.35 + 5.29 + 5.46 + 5.4 + 5.95 + 6.22 + 5.43 +5.48 +6.06 +5.33 +5.46 +5.41)
= --------------------------------------------------------------------------------------------------------------
12
= 5.57
theoretically.. the higher the pH values should be between 0 to 14.
based from the above results, the mean tap water has an average of 7.016 and by looking at the pH chart... its a neutral or pure water.
while the average pH Bottles has 5.57, this means its more acidic water, or by looking at the pH chart its an acid rain water.
a 6.32pH is below pure water, based on the chart looks like a urine/saliva.
Try to get to every number from 1 to 10 using four 4's and any number of arithmetic operations (+, −, ×, ÷). You may also you parentheses.
Answer:
Step-by-step explanation:
1. 4/4+4-4=1
2. 4/4+4/4=2
3. 4+4/4-4=3
4. 4 × (4 − 4) + 4=4
5. (4 × 4 + 4) / 4=5
6. 44 / 4 − 4=6
7. 4+4-4/4=7
8. 4+4+4-4=8
9. 4+4+4/9=9
10. 44 / 4.4=10
Answer:
1 = (4 x 4)/(4 x 4) or (4 + 4)/(4 + 4) or (4 / 4) x (4 / 4) or (4 / 4)/(4 / 4)
2= (4 x 4)/(4 + 4) or 4 / ((4+4)/4)
3= (4 + 4 + 4)/4 or (4 x 4 - 4)/4
4 = 4 - (4 - 4)/4
5 = (4 x 4 + 4)/4
6 = 4 + (4 + 4)/4
7 = 4 - (4/4) + 4
8 = 4 + (4 x 4)/4
9 = 4 + 4 + (4/4)
10 - I tried the best. You might need ! or sqrt operator to get 4.
Updated:
I forgot we could use 4, 44, 444, or 4444, so that 10 could be expressed as:
10 = (44 - 4)/4
URGENT, PLEASE HELP! (4/5) -50 POINTS- ! please no wrong answers for the points.! A) y = -3x + 2 B) y = -x + 2 C) y = 3x + 2 D) y = x + 1
Answer:
D y= x+1
Step-by-step explanation:
The line has a positive slope since it goes up from left to right
We can eliminate A and B
3 is a fairly steep slope for line C
Lets check with point x=7
y = 3*7 +2 = 21+2 = 23
Way too steep
Lets check 2
y = 3*2+2 = 6+2 = 8
Still above the points
Checking D
y = x+1
x=7
y = 7+1 =8 A little high
x=2
y = 2+1 =3 A little low but much better than C
Answer:
[tex]\huge \boxed{y=x+1}[/tex]
Step-by-step explanation:
Using a graph,
we can see the line y=x+1 is best fit for the data.
Factor the expression completely. 6×3- 4×2 – 16x A. 0 B. 2x(3×2 – 2x – 8) C. 2x(3x + 4)(x – 2) D. 4x(2x + 1)(x – 4) E. 2x(2×2 + 7x – 4) ill give brainliest
Answer:
The answer is option CStep-by-step explanation:
6x³ - 4x² - 16x
To factorize the expression first factor out the GCF out
The GCF in the expression is 2x
That's
2x( 3x² - 2x - 8)
Next Factorize the terms in the bracket
To factorize write - 2x as a difference
that's
2x( 3x² + 4x - 6x - 8)
Factor out x from the expression
2x [ x( 3x + 4) - 6x - 8 ]
Next factor out - 2 from the expression
2x [ x ( 3x + 4) - 2( 3x + 4) ]
Factor out 3x + 4 from the expression
We have the final answer as
2x( 3x + 4)( x - 2)Hope this helps you
The length of a rectangle is twice the width. If the length is increased by 4 inches and the width is decreased by 1 inch, a new rectangle is formed whose perimeter is 198 inches. Find the dimensions of the original rectangle.
Answer:
Width: 32 inches.
Length: 64 inches.
Step-by-step explanation:
Let's say that the width of the rectangle is x inches, so the length is 2x inches.
If 2x + 4 and x - 1, the perimeter is 198 inches. That means that two times the width plus two times the length is 198 inches.
2(2x + 4) + 2(x - 1) = 198
4x + 8 + 2x - 2 = 198
6x + 6 = 198
x + 1 = 33
x = 32.
That means that the width of the original rectangle is 32 inches, and the length is 32 * 2 = 64 inches.
Hope this helps!
Find y. A. √22 B. 8 C. √42 D. 4
Answer:
[tex]\Large \boxed{\mathrm{D. \ 4}}[/tex]
Step-by-step explanation:
The triangle is a right triangle.
We can use trigonometric functions to solve the problem.
tan θ = opp/adj
tan 30 = y/(4√3)
y = 4√3 tan 30
y = 4
If √2x - 1 + 2=5, then x is equal to?
Answer:
x = 5
Step-by-step explanation:
Remove the radical by raising each side to the index of the radical.
x = 5
This was done assuming that 2x-1 was under the radical and that +2 wasn't.
Hi everyone how to solve this question
$2x+7$
according to the flow chart,
1. multiply [tex] x[/tex] by $2$, so $2x$
and then add seven to it so $2x+7$
note, if the order was reverse, i.e. first add seven ($x+7$). then multiply by two ($2(x+7)$)
the answer would be $2x+14$
Find the missing probability.
P(A) = 23,P(An B)= P(B|A) =?
Answer:
the formular is
p(B/A)=P(AnB)/P(A)
so the missing probability is:-
P(AnB)=P(B/A)×23
And the other missing probablility is:-
p(B/A)=P(AnB)/23
Simplify the expression 3-8x3-4
Answer:
−8x3−1
Step-by-step explanation:
let's simplify step-by-step.
3−8x3−4
=3+−8x3+−4
Combine Like Terms:
=3+−8x3+−4
=(−8x3)+(3+−4)
=−8x3+−1
Answer:
-1 - (2x^3)^3
Step-by-step explanation:
The equation is:
=> 3 - 8x^3 - 4
=> -1 - 8x^3
=> -1 - (2x^3)^3
Which paper folding method can be used to form a perpendicular line segment
Answer:
Begin with a line segment on the paper and fold the paper so that the segment's endpoints lie on top of each other
Billy has x marbles. Write an
expression for the number of
marbles the following have…
a) Charlie has 5 more than Billy
b) Danny has 8 fewer than Billy
c) Eric has three times as many as
Billy
Answer:
[tex]Charlie = 5 + x[/tex]
[tex]Danny = x - 8[/tex]
[tex]Eric = 3x[/tex]
Step-by-step explanation:
Given
Billy's Marble = x
Required
Determine a,b and c
a. Charlie's Marble
"5 more" means 5 + or + 5
Since Billy's Marble is represented with x, then Charlie's Marbles will be
[tex]Charlie = 5 + x[/tex]
b. Danny's Marbles
Having "8 fewer" means we have to subtract 8 from Billy's marble;
Since Billy's Marble is represented with x, then Danny's Marbles will be
[tex]Danny = x - 8[/tex]
c. Eric Marbles
Having "three times as " means we have to multiply Bill's marble by 3;
Since Billy's Marble is represented with x, then Danny's Marbles will be
[tex]Eric = 3 * x[/tex]
[tex]Eric = 3x[/tex]
