Question

Samantha's car used 2 5/8 gallons to travel 147 miles. How many miles can the car go on one gallon of gas?

Answer 1

let's firstly convert the mixed fraction to improper fraction.

`\stackrel{mixed}{2(5)/(8)}\implies \cfrac{2\cdot 8+5}{8}\implies \stackrel{improper}{\cfrac{21}{8}} \\\\[-0.35em] ~\dotfill\\\\ \begin{array}{ccll} gallons&miles\\ \cline{1-2} (21)/(8) & 147\\[1em] 1& m \end{array} \implies \cfrac{(21)/(8)}{1}~~=~~\cfrac{147}{m}\implies \cfrac{21}{8}=\cfrac{147}{m} \\\\\\ 21m=(8)(147)\implies m=\cfrac{(8)(147)}{21}\implies m=56`