Question

A swimming pool is 50 m long and 15 m wide. Its shallow and deep ends are 1.5 m and 4.5 m respectively. If the bottom of the pool slopes uniformly, find the amount of water in kilolitres required to fill the pool (1 m³ = 1000 liters).

Answer 1

Area of cross section = Area of trapezium

= `(1)/(2) xx ("sum of parallel sides") xx "height"`

= `(1)/(2) xx (1.5 + 4.5) xx 50`

= `(1)/(2) xx 6 xx 50`
= 150m²
∴ Volume of the pool
= area of cross section x height
= 150 x 15
= 2250m³   ...(∵ 1m3 = 1kilolitres)
∴ Volume of the pool is 2250kilolitres.