In One Fortnight Of A Given Month, There Was A Rainfall Of 10 CM In A River Valley. If The Area Of The Valley Is 97280KM Show That The Total Rainfall Was Approximately Equal To The Addition To The Normal Water Of Three Rivers Each 1072 Km ,75 KM Wide And 3M Deep.

So, then using simple volume formulas for cuboid, where volume = l × b × h or area × h

The volume of rainfall in the area = 7280 ×10 × 0.00001 km^{3} = 0.728 km^{3}

Volume of water in 3 rivers = 3 ×1072 × 75 × 0.001 × 3 × 0.001 km^{3} = 0.723 km^{3}

Hence, the 2 values are nearly similar.