A water tap fills a tub in ‘p’ hours and a sink at the bottom empties it in ‘q’ hours. If p < q and both tap and sink are opened the tank is filled in ‘r’ hours, then the relation b/w p, q and r is:
Answer & explanation
Correct answer: option 2
According to question ,
∵ p < q,
∴ On opening pipe and sink together,
part of the tub filled in 1 hour = \(\frac{1}{p}\) - \(\frac{1}{q}\)
hence , \(\frac{1}{p}\) - \(\frac{1}{q}\) = \(\frac{1}{r}\)