When the price of a toy was increased by $20 \%$,the number of toys sold was decreased by $15 \%$. What was its effect on the total sales of the shop?

In an examination,$35 \%$ of the students passed and $455$ failed. How many students appeared for the examination?

When a number is divided by $12$,the quotient becomes $1/4$ of another number. By what percentage is the first number greater than the second number?

$A$ reduction of $10 \%$ in the price of tea enables a dealer to purchase $25 \ kg$ more tea for $Rs \ 22500$. What is the reduced price per $kg$ of tea?

In a motor of $120$ machine parts,$5 \%$ parts were defective. In another motor of $80$ machine parts,$10 \%$ parts were defective. For the two motors considered together,the percentage of defective machine parts was (in $\%$)

If $50 \%$ of $(x-y) = 30 \%$ of $(x+y)$,then what percent of $x$ is $y$?