The amount used to purchase one litre of petrol can be used to purchase 3litre of diesel or 5 litre of kerosene .out of a certain amount ,Rs.510 is spent on diesel
What will be the total amount to purchase 4litres of each of the 3 liquids at the above rate
We do not do your homework for you. Although it might take more effort to do the work on your own, you will profit more from your effort. We will be happy to evaluate your work though.
However, I will give you a start.
4/3 * 510 = cost of diesel