$A$ housewife saved $₹ 2.50$ in buying an item on sale. If she spent $₹ 25$ for the item,approximately what percentage did she save in the transaction?

$x\%$ of $360 = 129.6$. Find $x$.

The average marks obtained in a class of $50$ students is $70 \%$. The average of the first $25$ students is $60 \%$ and that of the next $24$ students is $80 \%$. What is the percentage of marks obtained by the last student?

Pradeep invested $20\%$ more than Mohit. Mohit invested $10\%$ less than Raghu. If the total sum of their investment is $₹ 17,880$,how much amount did Raghu invest?

To attract more visitors,the zoo authority announces a $20 \%$ discount on every ticket,which costs $25 \ p$. For this reason,the sale of tickets increases by $28 \%$. Find the percentage of increase in the number of visitors.

If the price of petrol is increased by $20 \%$,by what percentage should the consumption be decreased by the consumer,if the expenditure on petrol remains unchanged (in $\%$)?