A milk tank at a dairy has inlets of two types P and Q. All inlets of type P, when open, bring in milk at the same rate; all inlets of type Q, when open, bring in milk at the same rate. The empty tank is completely filled in 20 minutes if 8 inlets of type P and 6 inlets of type Q are open, and in 30 minutes if 4 inlets of type P and 12 inlets of type Q are open. In how many minutes will the empty tank get completely filled if 5 inlets of type P and 15 inlets of type Q are open? can we create two eq for p and q and make them equal
1 Answer
nav · 2026-06-16 · 2 helpful
Great question! so, let the rate of filling of type P be p and type Q be q. now 8 inlets of P at the rate of p and 6 inlets of Q at the rate of q fill tank in 20 mins so in 1 min they fill 1/20 tank => 8p+6q=1/20. similarly 4p+12q=1/30. on equating these both we get values of p and q. finally we take 5p+15q and put values of p and q to get our final answer as 24 minutes :)