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 re: Initial observation by Charlie)

The emptying rate is noted as relevant.  The doubling of the rate of the rainfall after beginning to empty the containers would only be relevant if, while emptying the containers, the rain continued to fill them at the same time.  If this were the problem being posed, I believe it would take a bit of calculus to determine at what limit the container was to be considered "emptied".

Posted by Dej Mar on 2008-11-06 07:27:49