Question

The cross section of a canal is trapezium in the shape through which water is flowing
with a speed of 3 km./min. The canal is 12m wide at the top and 8m wide at the bottom.
If the depth of the canal is sum of ten times the bottom width and one-third of the top
width, how many litres of water will flow through it in 2 seconds?​

Answer 1

Answer:

Let the depth be x 

2x(12+8)=840

2x×20=840⇒x=84 m

Answer 2

Answer:

I think this will help you

Step-by-step explanation:

let the depth be h m

Area of trapezium = 84 m2

=> Area of ABC + area of ADC = 84 m2

=> 1/2 (AB) (DE) + 1/2 (DC) (DE) = 84

=> 1/2 (12) (h) + 1/2 (8) (h) = 84

=> 6h + 4h = 84

=> 10h = 84

=> h = 84/10

=> h = 8.4

Hence the depth of the canal is 8.4 m.