Question

Q15. A tap can empty a tank in 1 h. A second tap can empty it in 30 min. If both the taps operate simultaneously, how much time is needed to empty the tank?

Answer 1

first tap work done is 1/60. 1hr=60min
Sec tap work done is 1/30
both taps can do I 1/60 + 1/30 = 1/20
hence both can empty in 20min