Question

A and b are two taps which can fill a tank individually in 10 minutes and 20 minutes respectively. However, there is a leakage at the bottom which can empty a filled tank in 40 minutes. If the tank is empty initially, how much time will both the taps take to fill the tank (leakage is still there)? Select one: a. 8 minutes b. 7 minutes c. 30 minutes d. 10 minutes

Answer 1

Answer:

a.8 minutes

Step-by-step explanation:

Tap A's 1 minute work=1/10 part filling

Tap B's 1 minute work=1/20 part filling

Leakage C's 1 minute work =1/40part emptying(Since we take the leakage as C)

= -1/40 part filling(Since emptying something means negative amount of something being filled)

So when three taps are opened together,

(A+B+C)s 1 min work=(1/10 +1/20 -1/40) part filling

=(4+2-1/40) part filling (Since LCM of 10,20 and 40 is 40)

=5/40 part filling

=1/8 part filling

So, Time taken to fill the tank={1/(1/8)}

=(1×8) minutes

=8 minutes ........... ANSWER