Assume that the average volume of a raindrop is 10 cubic millimetres. A city spread in 10 km x 10 km received 1 cm of rain. The number of raindrops that fell on the city is
Dimensions of city after rainfall = 10km x 10km x 1 cm
=> Volume = $$10^7\times10^7\times10$$ mm
= $$10^{15}$$ mm
Volume of raindrop = $$10$$ $$mm^3$$
$$\therefore$$ Number of raindrops = $$\frac{10^{15}}{10}=10^{14}$$
=> Ans - (D)