Question

1. An inlet pipe can fill a tank in 10 hrs and
an outlet pipe empties the same full tank
in 20 hrs. The time required to fill the tank
when both pipes are opened.
(a) 10
(b) 20
(d) 25
(c) 30
ases by 10% in​

Answer 1

Answer:

let the volume of tank be v litres

hence when outlet is closed water is filled in 10h

rate of inflow =

$\frac{v}{10}$

similarly rate of outflow is

$\frac{v}{20}$

now let when both the otlets are opened water fills in t hrs

so

$\frac{vt}{10} - \frac{vt}{20} = v$

this gives t=20hrs