Question

The gasoline gauge read 1/4 full. When 12 gallons were added to the tank the gauge read 3/4 full. How many more gallons to fill the tank

Answer 1

Initially, 1/4 of the tank was filled.

After adding 12 gallons, it was 3/4 full.

Increase in fuel filled portion =
$\frac{3}{4} - \frac{1}{4} = \frac{3 - 1}{4} = \frac{2}{4}$

So 2/4 of the tank = 12 gallons

1/4 of tank = 12 ÷ 2 = 6 gallons

4/4 of tank = 6×4 = 24 gallons
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Portion remaining to be filled =

$1 - \frac{3}{4} = \frac{4 - 3}{4} = \frac{1}{4}$

Fuel needed = 1/4 × 24 = 6 gallons

So you need 6 more gallons to fill the tank