The gasoline gauge on a van initially read one third

1

3 full. When 1010 gallons were added to the tank, the gauge read three fourths

3

4 full. How many more gallons are needed to fill the tank?

3/4 - 1/3 = 9/12 - 4/12 = 5/12

(5/12) / 10 = 1 / x

5/12x = 10

x = 10 * 12/5

x = 120/5 = 24 gallons ... so when full, the tank holds 24 gallons

so if it is already 3/4 full, then u just need 1/4 to fill

1/4 (24) = 24/4 = 6 ... so u would need 6 more gallons to fill the tank up to full capacity.