Question

The length and width of a swimming pool are 50 metres and 15 metres respectively. If the depth of the swimming pool at one end is 10 metres and at the other end 20 metres, then find the volume of water in the swimming pool ? 

(a) 10000 m³ 

(b) 11250 m³ 

(c) 15000 m³ 

(d) 8000 m³ 

Answer 1

(b) 11250 m³

If we take the vertical crossection of the face of the swimming pool, then it is a trapezium ABCD, with parallel sides AD and BC respectively of lengths 10 m and 20 m and distance between parallel sides as 50 m. The width of the swimming pool is 15 m.

∴ Volume of water in the swimming pool 

= Area of vertical cross section (ABCD) × width of swimming pool

= \(\big[\frac12(10+20)\times50\big]\times15\) m³

= (15 x 50 x 15) m³ = 11250 m³.