Area of the valley, A = 97280 km2
Level in the rise of water in the valley, h = 10 cm = (10/100000) km = (1/10000) km
Thus, amount of rain fall = Ah = 97280 km2 × (1/10000) km = 9.828 km3
in 14 days 9.828km3 in 1 day 0.702km3
Volume of water in each river = length × breadth × height = 1072 km × 75 m × 3 m = 1072 km × (75/1000) km × (3/1000) km = 0.2412 km3
Thus, the volume of water in three rivers = 3 × 0.2412 km3 = 0.7236 km3
and amt of rainfall= 0.702 km3 which is approximately equal
This shows that the amount of rain fall is approximately equal to the amount of water in three rivers.