$$25\% \ of (50\% \ of \ 30\% \ of \ 150)\over 40\% of \ 2250$$ is equal to:

The value of 4÷12 of [3÷4 of {(4-2) x 6÷2}] -2x6÷8+3 is:

The value of $${0.7×0.7×0.7+0.3×0.3×0.3}\over {0.7×0.7-0.7×0.3+0.3×0.3}$$ is

Find the value of the given expression.

$$ \sqrt { 20-{ \sqrt { 20- \sqrt { 20- \sqrt { 20- .....∞}}}}} $$

Find the value of given expression. 

[76 – {90 ÷ 5 ⨯ (24 – 36 ÷ 3) ÷ 3}] 

$$ if \ {1\over x}+x=4,$$ then find $${1\over x^2}+x^2$$

For what value of m will the system of equations 18x-72y+13=0 and 7x-my-17=0 have no solution?

Find the value of given expression.

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