A computer repair person charges 50.00 dollars per hour, plus an additional mileage fee. The charge for mileage varies directly with the square root of the number of miles traveled. If one hour plus 25 miles traveled costs 140.00 dollars, what is the total amount charged for one hour plus 36 miles traveled?
- A) 218.00
- B) 196.92
- C) 179.60
- D) 158.00
- E) 143.60
The charge formula is $$ 50h+k\sqrt m$$ where $h$ stands for number of hours and $m$ stands for number of miles.
For $h=1$ and $m=25$ the charge is $140$, thus $$140= 50 + 5k$$
Solve for $k$ and we get $k=18$
Now if you plug $h=1$ and $m=36$ you find the charge to be $40+18(6)=158$
Therefore the correct answer is $(D)$