Question

A milk man mixed 1 : 4 solution of milk and water with another 1 : 2 solution of milk and water in the volume of ratio 3 : 2. If the profit earned by selling the first solution was 20% and the mixture was sold at the same price, what is the profit or loss percentage? You have to assume that water comes free of cost.
a. 5.26% profit
b. 5.25% loss
c. 6.25% loss
d. None of these; A milk man mixed 1 : 4 solution of milk and water with another 1 : 2 solution of milk and water in the volume of ratio 3 : 2. If the profit earned by selling the first solution was 20% and the mixture was sold at the same price, what is the profit or loss percentage? You have to assume that water comes free of cost.; a. 5.26% profit; b. 5.25% loss; c. 6.25% loss; d. None of these

Answer 1

Consider 90 litre of solution1 and 60 litre of solution2 

90 litre of solution1 contains 90*1/5=18 litre of milk and (90-18)=72 litre of water
60 litre of solution2 contains 60*1/3=20 litre of milk and (60-20)=40 litre of water

Mixture will have 18+20=38 litre of milk 72+40=112 litre of water
i.e., Quantity of milk : Quantity of water = 38 : 112 = 19 : 56

Take 75 litre of solution1. Quantity of milk = 75*1/5=15 litre. Profit earned in selling solution is 20%
assume cost price of 1 litre of milk = Rs.1
Cost price of 75 litre of solution1 = Rs.15.
Selling price of 75 litre of solution1 = 15*120/100 = Rs.18

Take 75 litre of mixture. Quantity of milk = 75*19/75=19 litre. 
Cost price is Rs.19
Selling price will be same and is Rs.18
so there will be a loss
Loss = Rs.1 in selling 75 litre of the mixture
Percentage loss = 1*100/19 = 5.25% loss

hope it helps....