A new car is purchased for 15700 dollars. The value of the car depreciates at 7.5% per year. To the nearest year, how long will it be until the value of the car is 10100 dollars?

10100=15700(1-0.075)^x

10100=15700(0.925)^x

divide both sides by 15700

0.925^x=101/157

convert decimal

(37/40)^x=101/157

take the log

x= log 37/40 (101/157)

x= 5.65824

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.

rick would give her the best deal as he will charge $8.88 per hour