What percent of $12$ is $84$?

If $25 \%$ of a number is $6$,what is the number that is $50 \%$ more than the initial number?

If $35 \%$ of $A$'s income is equal to $25 \%$ of $B$'s income,then the ratio of $A$'s income to $B$'s income is

The monthly income of a person is $Rs. 5000$. If his income is increased by $30\%$,then what is his monthly income now?

If $18 \%$ of a number is $720,$ then what is $81 \%$ of the same number?

In an examination,a candidate obtains $25\%$ marks and fails by $45$ marks,while another candidate obtains $46\%$ marks and passes by $15$ marks. What are the passing marks?