Paul has 3 large identical empty open-top containers (C1, C2, C3) outside.

- He walks outside and soon after, at time 0 hours, a steady rain begins. Rain enters the containers at R gallons per minute (gpm).
- 7 minutes later, Paul starts emptying out C1 at a rate of J gpm. Exactly when C1 is empty, Paul starts emptying C2 out and finishes 42 minutes later.
- Exactly when he's done emptying out C2, it starts raining twice as hard (2R gpm) and Paul starts emptying out C3 twice as fast (at 2J gpm).
-When Paul finishes emptying C3, the rain stops.

1) At what time did Paul start emptying C3?
2) At what time did it stop raining?

(In reply to Initial observation by Dej Mar)

But before he gets to C3, C3 has already been filling.  Doubling the rain rate and the emptying rate, allows that portion of C3's contents to go that much faster.

Posted by Charlie on 2008-11-05 22:10:24