Water in a canal, 6m wide and 1.5m deep, is flowing at a speed of 4km/h. How much area will it irrigate in 10 minutes, if 8cm of standing water is needed for irrigation?

Given: Width of the canal = 6m
Depth of the canal = 1.5m
Water is flowing at the speed of 4km/hr = 4000m/hr
Length of water column formed in 10 minutes = (10/60) hour = (1/6) hour = (1/6) x 4000 = 666.67m
Volume of water flowing in 10 minutes = Volume of the cuboid of length 666.67m, width 6m and depth 1.5m.
Volume of the water flowing in 10 minutes = 666.67 x 6 x 1.5 = 6000.03 ≈ 6000 m³
Let x m² area is irrigated in 10 minutes, then
x x (8/100) = 6000
x = 600000/8 = 75000 m²