Question

Question was provided via image upload.

Explanation:

Step1: Identify the amounts used

He used $\frac{5}{8}$ tank, $\frac{1}{2}$ tank, and $\frac{1}{4}$ tank.

Step2: Find a common denominator

The common denominator of 8, 2, and 4 is 8. Convert $\frac{1}{2}$ to $\frac{4}{8}$ and $\frac{1}{4}$ to $\frac{2}{8}$.

Step3: Add the fractions

Add $\frac{5}{8} + \frac{4}{8} + \frac{2}{8} = \frac{5 + 4 + 2}{8} = \frac{11}{8}$ or $1\frac{3}{8}$.

Answer:

$1\frac{3}{8}$ (or $\frac{11}{8}$) tanks of gas.