A rectangular container 110 cm by 60 cm by 46 cm was 10% filled with water. A tap was turned on to fill it up with water at a rate of 8 ℓ/min. Every 15 seconds after the tap was turned on, an iron ball of volume 300 cm3 was added to the container. How many iron balls of the same volume would there be in the container when the container is 100% filled with water?
Percentage of volume of space to be filled
= 100% - 10%
= 90%
Volume of space in the container
= 90% x 110 x 60 x 46
=
90100 x 110 x 60 x 46
= 273240 cm
3 1 ℓ = 1000 mℓ
8 ℓ = 8 x 1000 = 8000 mℓ
Number of sets of 15 seconds in 1 min
= 60 ÷ 15
= 4
Water flowed in every 15 seconds
= 8000 ÷ 4
= 2000 mℓ
Total volume added for every 15 seconds
= 2000 + 300
= 2300 cm
3 Number of sets of 2300 cm
3= 273240 ÷ 2300
= 118 r 1840
After the last iron ball is added, 1840 cm
3 of water will flow into the tank so that the container is 100% filled with water.
Number of iron balls added = 118
Answer(s): 118