gimana yak nomer 3....

banyak bensin yg dihabiskan
= 100 / 120 x 3
= 5/6 x 3
= 5/2 liter

Bensin yg dihabiskan= x

120/100 = 3/x
120x = 100.3
120x = 300
x = 300/120 = 2,5 L