Originally Posted by

**skystar** thanks,im still a bit confused, 1st time ive seen this sort of problem.

id be eternally grateful if you could give me an outline of the method for all general questions like this.heres another problem i have:

a mixing machine initially contains 10l of orange,machine switched on apple juice enters at a rate of 5l per min, and mixed leaves at same rate.write a differential equation for apple juice in the machine, calculate how many seconds after switch on that the machine contains equal amounts of apple and orange.