The monthly salary of Mr. Sachdev increases by $5 \%$,and as a result,his new annual salary becomes $₹ 15,120$. What was his earlier monthly salary (before the increase)?

If inflation increases at a rate of $8 \%$ p.a.,what will a $₹ 20$ article cost at the end of two years?

On decreasing the price of a colour $TV$ by $30 \%$,its sale is increased by $20 \%$. The effect on the revenue is:

$A$ boy found the answer for the question "subtract the sum of $\frac{1}{4}$ and $\frac{1}{5}$ from unity and express the answer in decimals" as $0.45$. The percentage of error in his answer was

Raja got $76 \%$ marks and Seema got $480$ marks in a test. The maximum marks of the test is equal to the marks obtained by Raja and Seema together. How many marks did Raja score in the test?

In an election between two candidates,$60 \%$ of the voters cast their vote,out of which $4 \%$ of the votes were declared invalid. $A$ candidate received $7344$ votes,which were $75 \%$ of the total valid votes. Find the total number of votes enrolled in the election.