CAT (QA) PYQs

A tank is fitted with pipes, some filling it and the rest draining it. All filling pipes fill at the same rate, and all draining pipes drain at the same rate. The empty tank gets completely filled in $6$ hours when $6$ filling and $5$ draining pipes are on, but this time becomes $60$ hours when $5$ filling and $6$ draining pipes are on. In how many hours will the empty tank get completely filled when one draining and two filling pipes are on?

Anil can paint a house in $12$ days while Barun can paint it in $16$ days. Anil, Barun, and Chandu undertake to paint the house for ₹ $24000$ and the three of them together complete the painting in $6$ days. If Chandu is paid in proportion to the work done by him, then the amount in INR received by him is

Three men and eight machines can finish a job in half the time taken by three machines and eight men to finish the same job. If two machines can finish the job in $13$ days, then how many men can finish the job in $13$ days?