UA-UMO 1997 Problem 91

There are four apples on a plate, of weights $600,400,300,$ and $250$ grammes. Two pupils take an apple each (one by one) and start eating simultaneously. A pupil can take another apple only after he has eaten the previous apple. It is assumed that they equaly fast (measured in grammes per second). How should the first pupil do in order to eat as large amount as possible?