You need to solve for one variable in equation 1 and substitute it in equation 2 to solve.
Equation 1: x+y=24
x= number of 3 pt questions
y= number of 5 pt questions
24= Total number of questions
Equation 2: 3x+5y=100
100= Total point value possible on test
3x= point value of 3 pt questions
5y= point value of 5 pt questions
x+y=24
Subtract y from both sides
x=24-y
Substitute in equation 2:
3x+5y=100
3(24-y) +5y=100
72-3y+5y=100
72+2y=100
Subtract 72 from both sides
2y=28
Divide both sides by 2
y=14
Substitute y=14 back in to solve for x:
3x+5y=100
3x+5(14)=100
3x+70=100
Subtract 70 from both sides
3x=30
Divide both sides by 3
x=10
So there are 10 three point questions
There are 14 five point questions.
Hope this helped! :)
Answer:
2401
Step-by-step explanation:
Given that we want to estimate average income in a population.
The standard deviation of income in the population is $1,000
We want confidence interval around our estimate to be +/- $40
i.e Margin of error = 40
We know that margin of error = Std error * Z critical for 95%
i.e. 
Std error = 
Together we get

I think you would multiply 20 × 4 and the answer would be 80 that the scientist counted the number of plants in each 4 sections after 20 days.
Answer:
$11,728
Step-by-step explanation:
Twice a year, for 4 years is 8 times
516×8 = 4128
Yearly for 4 years is 4 times
700×4 = 2800
Every month for 4 years is 48 times
100×48 = 4800
Minimum expenditure:
4128 + 2800 + 4800 = $11,728
Answer:
How many standard deviations above the mean is 14,500 hours? 1.25 1.5 2.5 Using the standard normal table, the probability that Seth's light bulb will last no more than 14,500 (P(z ≤ 1.25)) hours is about ✔ 89% .