8 rock in 5 minutes
54 rocks / 8 rocks = 6.75
6.75 x 5 minutes = 33.75 minutes
Devin borrowed $1,058 at 13 percent for nine months.
We have to calculate the interest paid.
Interest = 
Substituting the values of
Principal = $1058
Rate = 13%
Time = 9 months =
year
Interest = 
Interest = 103.155
= 103.16
So, Devin will pay 103.16 as the interest.
Therefore, Option A is the correct answer.
Answer:
<u>Given</u>:
- R(x) = 59x - 0.3x²
- C(x) = 3x + 14
<u>Find the following</u>:
- P(x) = R(x) - C(x) = 59x - 0.3x² - 3x - 14 = -0.3x² + 56x - 14
- R(80) = 59(80) - 0.3(80²) = 2800
- C(80) = 3(80) + 14 = 254
- P(80) = 2800 - 254 = 2546