Please help in the solution the following problem In what proportion must water be mixed with milk so as to gain 20% by selling the mixture at the cost price of the milk ? How to solve this kind problem , is there any general method/formula .

general method/formula .

suppose the original quantity is x units and rate is Rs 1/unit the C.P. = x.1 = Rs x suppose it is adulterated with y % of fake item new quantity is x+(y% of x) the S.P. is also 1 the cash inflow = [x+(y% of x)].1 profit = [x+(y% of x)] minus x = y% of x percentage profit = (y% of x)/x = y % i.e. if profit required is y% adulteration required is y% if profit required is 20% adulteration required is 20 %(i.e. 1/5)

Lets suppose , we have 100

Lets suppose , we have 100 litres of milk , cost price is 1 rs per litre so cost price of 100 ltr milk is 100 rs. Now u want to add water to have 20% profit , and u want to sell it on same cost price ( 1 rs ). So you want to make 120 rs out of this 100 rs. Add 20 litres of water , ur mixture now = 120. sell it at 1 rs per litre so the cost = 120. So the water added is 1/5 of the milk to gain 20% profit.

Good Explanation Why dont

Good Explanation Why dont you register in this site so that we can know more about you Btw Nice to see the site is back and ppl started using the forum.