Question

A river 1.5 m deep and 30 m wide is flowing at the rate of 3 km per hour. The volume of water that runs into the sea per minute is
(a) 2000 m³
(b) 2250 m³
(c) 2500 m³
(d) 2750 m³

Answer 1

(b) 2250 m³

Length of the river = 1.5 m
Breadth of the river = 30 m
Depth of the river = 3 km = 3000 m

$$\begin{gathered} \mathrm{Now},\mathrm{volume}\mathrm{of}\mathrm{water}\mathrm{that}\mathrm{runs}\mathrm{into}\mathrm{the}\mathrm{sea}=1.5\times 30\times 3000{\mathrm{m}}^3 \\ =135000{\mathrm{m}}^3 \end{gathered}$$

∴ Volume of water that runs into the sea per minute = $\frac{135000}{60}=2250{\mathrm{m}}^3$