The sum of the square of the first number and the cube of the second number is $568$ together. Also square of the second number is $15$ less than the square of $8$. What is the value of three-fifth of the first number? (assuming both the numbers are positive)

By how much is $\frac{5}{12}$th of $516$ lesser than $\frac{4}{9}$th of $495$?

What approximate value should come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value.)

$\sqrt{253}\times {\left(12.8\right)}^2=?$

What approximate value should come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value.)

$17.8\%$ of $370+24.9\%$ of $740=?$

What approximate value should replace the question mark (?) in the following equation? (You are not expected to calculate the exact value.)

$7080÷925\times 741-172=?$

What approximate value should come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value.)

$\left(17.7\times 28.9\right)÷{\left(32.8-17.4\right)}^2=?$