The marked price of a TV set is $₹7860$. $5\%$ is charged as sales tax, and if the cost of the TV set is $₹k$, then find the value of $k$.

A survey was carried out to find out the hobbies of students in a school. The report is represented in a pie chart given below.

Find the value of $x$.

A survey was carried out to find out the hobbies of students in a school. The report is represented in a pie chart given below.

Calculate the percentage of students whose hobby is watching movies.

The cost of turfing a rectangular field at $50$ paise per square meter is $₹575$. If the perimeter of the field if its sides are in the ratio $7:4$ is $k \mathrm{cm}$ (correct up to the nearest whole number), then find the value of $k$.

A number consists of two digits whose sum is $13$. If $27$ is added to the number, its digits are reversed. Find the number.