If Rs. $2800$ is $\frac{2}{7}$ of the value of a house,what is the total worth of the house (in Rs.)?

$x$ is $30 \%$ more than $y$ and $25 \%$ less than $z$. If the value of $y$ is $₹ 300$,then what is the value (in $₹$) of $z$?

Rajeev buys goods worth Rs. $6650$. He gets a rebate of $6\%$ on it. After getting the rebate,he pays sales tax at the rate of $10\%$. Find the total amount he will have to pay for the goods.

If the price of apples goes down by $10 \%,$ find the percentage of increase that a family should effect in its consumption so as not to increase expenditure on this account.

Two numbers are less than a third number by $30 \%$ and $37 \%$ respectively. How much per cent is the second number less than the first (in $\%$)?

If $A$'s salary is $50 \%$ more than that of $B$,then $B$'s salary is less than $A$'s by