WAEC Mathematics 2023 Paper

given that diameter = 140cm ⇒radius = 70cm, volume of cylinder = 200litres = $\text{200,000 cm}^3$

volume of cylinder = base area times height = $\pi r^2 h$

$\text{200,000 cm}^3 = \frac{22}{7} \times 70 \times 70 \times h$

$200,000 = \frac{107,800h}{7}$

cross multiply

1,400,000 = 107,800h

$h = \frac{1,400,000}{107,800}$

= 13cm (to the nearest cm).