The price of electricity has been increased by $25 \%$. If a person wants to keep the expenditure same,then the percentage reduction in use of electricity should be: (in $\%$)

Ishan spent $Rs. 35645$ on buying a bike,$Rs. 24355$ on buying a television,and the remaining $20\%$ of the total amount he had as cash with him. What was the total amount he had?

From the salary of an officer,$10\%$ is deducted as house rent,$15\%$ of the rest he spends on children's education,and $10\%$ of the balance,he spends on clothes. After this expenditure,he is left with $₹ 1377$. His salary is:

Ram donated $4 \%$ of his income to a charity and deposited $10 \%$ of the rest in a bank. If now he has $Rs$ $8640$ left with him,then his income is

In an examination,there were $2000$ candidates,out of which $900$ candidates were boys and the rest were girls. If $32 \%$ of the boys and $38 \%$ of the girls passed,then the total percentage of failed candidates is:

An army lost $10 \%$ of its men in war,$10 \%$ of the remaining due to diseases,and $10 \%$ of the rest were hurt. Thus,the strength was reduced to $729000$ active men. Find the original strength.