A shopkeeper loses $7 \%$ by selling a cricket ball for $Rs.\,31.$ For how much should he sell the ball so as to $\operatorname{gain} 5 \% ?$ (in $Rs.$)

A sold a horse to $B$ for $Rs.\, 4800$ by losing $20 \%$. $B$ sells it to $C$ at a price which would have given $A$ a profit of $15 \% .$ $B's$ gain is (in $Rs.$)

A manufacturer undertakes to supply $2000$ pieces of a particular component at $Rs.\, 25$ per piece. According to his estimates, even if $5 \%$ fail to pass the quality tests, then he will make a profit of $25 \% .$ However, as it turned out, $50 \%$ of the components were rejected. What is the loss to the manufacturer ? (in $Rs.$)

List price of a book is $Rs.\,100.$ A dealer sells three such books for $Rs.\, 274.50$ after allowing discount at a certain rate. Find the rate of discount in $\%$

Profit earned by an organization is distributed among officers and clerks in the ratio of $5: 3 .$ If the number of officers is $45$ and the number of clerks is $80$ and the amount received by each officer is $Rs.\,25,000,$ what was the total amount of profit earned? (in $Rs.$.......$lakhs$)

A shopkeeper professes to sell his goods at cost price but uses a weight of $800\, g$ instead of kilogram weight. Thus, he makes a profit of