#### Answer

Estimate 42 gallons
Exact $41 \frac{5}{8}$ gallons

#### Work Step by Step

Estimate
$148 - 69 - 37 = 42$
Exact
$147 \frac{1}{2} - 68 \frac{1}{2} - 37 \frac{3}{8}$ =
$147 \frac{1}{2} - 68 \frac{1}{2} - 37 \frac{3}{8}$ =
$79 - 37 \frac{3}{8}$ =
$78 \frac{8}{8} - 37 \frac{3}{8}$ =
$41 \frac{5}{8}$