Question

A tank can be filled by a tap in 20 min and by another tap in 25 min both the taps, are kept open for 5 min and then the second is tuned off , the tank will be completely filled in?

Answer 1

Maybe its "NO".

Because average time needed for the tank to get filled is 20 minutes but here we are filling it over just for 10(approx) minutes.

Also, if we have a determined time for which the first tap is kept open then we can determine the answer completely.

Hape its helpful.

Pls follow. Thanx.

Answer 2

Answer:-

here your answer..................

14 minutes.

Explanation:-

first tap can fill tank in 20 minutes

in one minute = 1/20

second tap can fill tank in 25 minutes

in one minute = 1/25

[first tap + second tap] one minute work is

1/20 + 1/25 = [ 5 + 4 ]/100 = 9/100

Now,

amount of work completed in 5 minutes

5 × 9/100 = 9/20

So, Remaining work

1 - 9/20 = [ 20 - 9 ]/20 = 11/20

then the remaining work has to be done

by first tap

because second one is turned off.

work will be completed by first tap in

[ 9/20 ] × 20 = 9 minutes

Hence

First tap can fill remaining tank in

9 minutes.

therefore the tank will be completly

filled in [ 5 + 9 ] = 14 minutes.