Question

a tap fills a water tank in 5 hours another time empty the full tank in 10 hours how long will it take to fill the tank if the water tank is empty and both the taps are open

Answer 1

Answer:

Step-by-step explanation:

Let the rate of which water is filled =x lit/hr

∴    Volume of tank =5x litre

Let the rate at which water is drained =y lit/hr

A/Q,  6(x−y)=5x

⇒6x−6y=5x

⇒6y=x

⇒y=x/6

Time to taken water completely =  

y

5x

​  

=  

x/6

5x

​  

=30 hrs  

Answer 2

Answer:

ans = 10

Step-by-step explanation:

flowrate = capacity/time

assuming capacity = x

then

flowrate of filling tap = x/5

and

flowrate of emptying tap = x/10

as these both taps are against each other :-)

we substract

hence resultant flowrate

= x/5 - x/10

=x/10

substituting in the original formula

f=c/t

x/10 = x/resultant time

hence we need 10 hrs to fill the whole tank