2015 · Q3
A milkman claims to sell milk at its cost price only. Still he is making a profit of 20% since he has mixed some amount of water in the milk. What is the percentage of milk in the mixture ?
Elementary MathematicsNumber System
- A200/3\%
- B75\%
- C80\%
- DTM %
Explanation
Let the mixture contain a fraction m of milk (water costs nothing). Selling 1 litre of mixture at the cost price of 1 litre of milk gives revenue proportional to 1 and cost proportional to m, so profit = (1 - m)/m = 20% = 1/5. Then 1 - m = m/5, so m = 5/6 = 83.33% = 250/3%. Hence option (d).