Lal & Jain Solutions for Exercise 1: Exercise

A trader bought $20 kg$ of wheat at $Rs. 6.50$ per $kg$ and $30 kg$ of wheat at $Rs. 7$ per $kg$. He sold the mixture at a profit of $Rs. 60$. At what price did he sell per $kg$ of the mixture of wheat?

How much water should be added to $175$litre of milk at $Rs. 8.00$litre so as to have a mixture worth $Rs. 7.00$per litre?

How much wheat at $Rs. 4$ per $kg$ should be mixed with $42 kg$ of wheat at $Rs. 6$ per $kg$ so as to have a mixture worth $Rs. 4.80$ a $kg$?

Two alloys of gold and copper are prepared by mixing in the ratio of $7:2$ and $7:11$. A third alloy is made after mixing the equal quantities of two alloys. The ratio of gold and copper in third alloy is:

A man buys milk at a certain price and after mixing it with water sells it again at the same price. How many $ml$ of water he mixes in a litre of milk if he makes a profit of $20\%$?

A mixture of $40$ litres of milk and water contains $10\%$ of water. How much water must be added to make the water $20\%$ of the resulting mixture?

Pure ghee costs $Rs. 100$ per $kg$. After adulterating it with vegetable oil costing $50$ per $kg$ , a shopkeeper sells the mixture at $Rs. 96$ per $kg$, thereby making a profit of $20\%$. In what ratio does be mix the two?

By mixing two qualities of pulses in the ratio $2:3$ and selling the mixture at the rate of $Rs. 22$ per $kg$, a shopkeeper makes a profit of $10\%$. If the cost of smaller quantity be $Rs. 14$ per $kg$, the cost per kg of the larger quantity is: