This is exactly same way i solved this in the mock and this was correct answer, but I was wondering, according to this formula, if his speed were to decrease, his mileage would increase by 0.5 miles per galon.
The question doesn't mention or eny anything about decreasing speed so i think this would be okay.
I was curious:
If it were said it decreases both way, we could use mod, but what would be the formula if reducing speed didn't affect the mileage
SaquibHGMATWhiz
ChandlerBong
Solomon's truck gets 24 mpg (miles per gallon) when driven at a speed of 40 mph (miles per hour) with no load. His truck's gas mileage decreases 1 mpg for each 500 pounds of added load and it decreases \(\frac{1}{2}\) mpg for each 10 mph of increased speed over 40 mph. Which of the following is a formula for the gas mileage of Solomon's truck when its speed is S mph (S >= 40) and it has a load of L pounds?
A. 24 - \(\frac{L}{500}\) - \(\frac{S}{2}\)
B. 24 - \(\frac{L}{500}\) - \(\frac{S}{20}\)
C. 26 - \(\frac{L}{500}\) - \(\frac{S}{20}\)
D. 44 - \(\frac{L}{500}\) - \(\frac{S}{2}\)
E. 44 - \(\frac{L}{500}\) - \(\frac{S}{20}\)
Solution: - Decrease because of L pounds weight \(= -\frac{L}{500}\)
- Decrease because of S speed \(=-\frac{1}{2}\times \frac{(S-40)}{10}=-\frac{S-40}{20}\)
- Final mileage \(=24-\frac{L}{500}-\frac{S-40}{20}\)
\(⇒24-\frac{L}{500}-\frac{S}{20}+\frac{40}{20}\)
\(⇒24-\frac{L}{500}-\frac{S}{20}+2\)
\(⇒26-\frac{L}{500}-\frac{S}{20}\)
Hence the right answer is
Option C