1. ## Need Assistance...

A vessel is full fo mixture of kerosene and petrol in which there is 18% kerosene.Eight litres are drawn off and then the vessel is filled with petrol.If the kerosene is now 15%, How much does the vessel hold?

Any help would be greatly appreciated.

Thanks,
Anshu

2. Originally Posted by Curious_eager
A vessel is full fo mixture of kerosene and petrol in which there is 18% kerosene.Eight litres are drawn off and then the vessel is filled with petrol.If the kerosene is now 15%, How much does the vessel hold?

Any help would be greatly appreciated.

Thanks,
Anshu
Assumptions: The contents of the vessel are well mixed (this means the composition you remove is the same throughout the vessel) and it is a binary mixture containing only petrol and kerosene

Let k = amount of kerosene, p = the amount of petrol and V = volume

$V = 0.18k + (1-0.18)p$ (eq1)

$V - 8 = 0.15k + (1-0.15)p$ (eq2)

Rearrange eq2: $V = 8 + 0.15k + 0.85p$ (eq3)

You now have two equations in k and p (V will cancel)