On dividing a number by $38$, we get $90$ as quotient and $19$ as remainder. What is the number?

$A$ and $B$ are positive integers. If $A + B + AB = 65$,then what is the difference between $A$ and $B$ (given $A, B \leq 15$)?

The sum of three numbers is $264$. If the first number is twice the second and the third number is one-third of the first,then the second number is:

The product of three consecutive even numbers is $4032$. The product of the first and the third number is $252$. What is five times the second number?

$42 \%$ of a number is $357$. What is $63 \%$ of that number?

Find the simplified value of $63 \sqrt{(729)^{-\frac{2}{3}}+(343)^{-\frac{2}{3}}} ?$