Question

Rain water from a rectangular 22 m $\times$ 20 m roof drains into a cylindrical vessel of diameter 2m and height 3.5 m. If the rain water collected from the roof fills $\frac{4}{5}$ th of the cylindrical vessel then find the rainfall in cm

• A. 4 cm
• B. 2 cm
• C. 7 cm
• D. 5 cm

Answer 1

The correct option is B

2 cm

Let the rainfall be h m

Volume of water collected in the cylindrical vessel = Volume of rain water drained from the roof

= $\frac{4}{5}\pi (1{)}^2\times \left(\frac{7}{2}\right)$ = $22\times 20\times h$

Hence h $=\frac{1}{50}m$

1m = 100 cm

Hence $\frac{1}{50}m$ = $\frac{100}{50}$ = 2 cm

Hence rainfall = 2cm