Find the value of given expression.

3 – (– 6) {– 2 – 9 – 3} ÷ 7{1 + (– 2) (– 1)}

Simplify : $$ {9\over 13} ÷{18\over 26}÷{90\over 52}$$

What will be the total number of pieces if the length of $$ {5}{1\over4}$$  the rib is cut to 3/4 m length?

If $${4x^2={15^2-9^2}}$$ then the value of x is

The smallest positive integer n for which 864 x n is a perfect cube, is: 

The smallest 4- digit number which is a perfect square is 

The sum of the squares of two positive integers is 100 and the difference of their squares is 28. The sum of the numbers is: 

There are some boys and girls in a room. The square of the number of the girls is less than the square of the number of boys by 28. If there were two more girls, the number of boys would have been the same as that of the girls. The total number of the boys and girls in the room are