In an election between two candidates,one got $52 \%$ of the total valid votes. $25 \%$ of the total votes were invalid. The total number of votes were $8400$. How many valid votes did the other person get?

An agent sells goods of value of Rs. $15000$. The commission which he receives is $12 \frac{1}{2} \%$. What is the commission amount?

In Mumbai,$60 \%$ of the registered voters are $BJP$-supporters and the rest are Congress-supporters. In a mayoral race,if $75 \%$ of the registered voters who are $BJP$-supporters and $20 \%$ of the registered voters who are Congress-supporters are expected to vote for candidate $X$,what percent of the registered voters are expected to vote for candidate $X$?

In a class,$70 \%$ of the students read Hindi,$40 \%$ of the students are boys,and $20 \%$ of the girls do not read Hindi. What percentage of boys read Hindi?

Peter could save $10 \%$ of his income. But two years later,when his income increased by $20 \%$,he could save the same amount as before. By what percentage has his expenditure increased?

$860 \%$ of $50 + 50 \%$ of $860 = ?$