A rectangular tank, 70 cm by 45 cm by 45 cm, is filled with water to a height of 6 cm. The ratio of the volume of water in the tank to that in a barrel is 5 : 4. If
25 of the barrel is filled with water, find
- the volume of the barrel.
- the minimum number of such barrels to fill the tank.
(a)
Volume of water in the tank
= 70 x 45 x 6
= 18900 cm
3 5 u = 18900 cm
3 1 u = 18900 ÷ 5 = 3780 cm
3 4 u = 4 x 3780 = 15120 cm
3 Volume of water in
25 of the barrel = 15120 cm
3 Volume of the barrel
= 15120 ÷
25 = 15120 x
52 = 37800 cm
3 (b)
Volume of the tank
= 70 x 45 x 45
= 141750 cm
3 Number of barrels to fill the tank
= 141750 ÷ 37800
= 3 r 28350
Minimum number of barrels to fill the tank
= 3 + 1
= 4
Answer(s): (a) 37800 cm
3; (b) 4