A rectangular tank, 90 cm by 50 cm by 40 cm, is filled with water to a height of 7 cm. The ratio of the volume of water in the tank to that in a pail is 9 : 4. If
25 of the pail is filled with water, find
- the volume of the pail.
- the minimum number of such pails to fill the tank.
(a)
Volume of water in the tank
= 90 x 50 x 7
= 31500 cm
3 9 u = 31500 cm
3 1 u = 31500 ÷ 9 = 3500 cm
3 4 u = 4 x 3500 = 14000 cm
3 Volume of water in
25 of the pail = 14000 cm
3 Volume of the pail
= 14000 ÷
25 = 14000 x
52 = 35000 cm
3 (b)
Volume of the tank
= 90 x 50 x 40
= 180000 cm
3 Number of pails to fill the tank
= 180000 ÷ 35000
= 5 r 5000
Minimum number of pails to fill the tank
= 5 + 1
= 6
Answer(s): (a) 35000 cm
3; (b) 6