The greatest number among $3^{50}, 4^{40}, 5^{30}$ and $6^{20}$ is

What least number should be subtracted from $3401$ so that the result is completely divisible by $11$?

$3 \frac{6}{7} + 6 \frac{1}{4} - 5 \frac{1}{3} + 2 \frac{1}{2} = ?$

How many positive factors of $160$ are there?

The difference between two positive integers is $3$. If the sum of their squares is $369$,then the sum of the numbers is

$\left[ {8\left\{ {\left( {\frac{{21 \times \sqrt {\frac{9}{{441}}} }}{5} \text{ of } 60\% - \frac{1}{5}} \right) \times 625 + 7} \right\} \div 4} \right] = ?$