A pool measuring 40 m x 20 m x 2 m was completely filled with water. The water was draining out of the tank at a constant rate and became completely empty after 20 minutes.
- What fraction of the pool was filled with water at the end of 19 minutes? Express your answer in the simplest form.
- How many litres of water was drained out of the pool at the end of 9 minutes?
(a)
Fraction of the pool empty per minute =
120 Fraction of the pool empty at 19
th minute
=
120 x 19
=
1920 Fraction of the pool still filled with water
= 1 -
1920 =
2020 -
1920 =
120 (b)
Volume of the pool
= 40 x 20 x 2
= 1600 m
3 = 1600 ℓ
Volume of water drained per minute
= 1600 ÷ 20
= 80 ℓ/min
Volume of the pool drained after the end of 9 minutes
= 9 x 80
= 720 ℓ
Answer(s): (a)
120; (b) 720 ℓ