If the irrigation efficiency is 80%, conveyance losses are 20% and the actual depth of watering is 16 cm, the depth of water required at the canal outlet, is

For the given values:
Irrigation efficiency ( E = 0.80 )
Conveyance losses ( L = 0.20 )
Actual depth of watering ( D_actual = 16 cm} )
Substitute these values into the formula:

D_outlet = D actual ÷ [E ×(1 - L)]

{D_outlet} = (16)÷{0.80 (1 - 0.20)} =
{16}÷{0.80 x0.80} = {16}÷{0.64} = 25 { cm}
Thus, the depth of water required at the canal outlet is 25 cm.

Efficiency is 80%, means 100 will be 80. and conveyance losses are 20%, which reflects remaining 80 will shrink to 64.
100 at outlet will be 64 at final.
25*64/100 = 16
so, 25 is the answer

Manas Ranjan is right

Explain please

Loss 20% means efficiency is 80 %

80%[80%*X]=16
X=25

Depth of water required considering conveyance losses = 16/0.8 20 cm (20% is lost in conveyance means only 80% in reached. So we have to provide more depth of water). Irrigation efficiency is 80% (means if I provide 20 cm depth of water then only 80% land will get irrigated). To make 100 % irrigation, Depth of water from canal outlet 20/0.8 25 cm.
I hope its clear.

Look efficiency is 80% means if we put 100ltrs it will reach 80ltrs in 80 ltrs loss is 20%so
80*(20/100)=16ltr
So total loss 20+16=36
100-36=64
64 % water reach to field whichi is 16cm
16*(100/64)= 25cm

It is 16/.8=20
Then 20*1.20= 24 exact ans

Depth of water while considering conveyance losses = 16/0.8 = 20 cm (conveyance loss=20%)
Irrigation efficiency is 80%
Depth of water from canal outlet = 20/0.8 = 25 cm.

Depth of water while considering conveyance losses = 16/0.8 = 20 cm (conveyance loss=20%)
Irrigation efficiency =80%
Depth of water from canal outlet = 20/0.8 = 25 cm.

Explain please