What is the value of $5 \frac{1}{2} + 7 \frac{1}{2} + 11 \frac{1}{2}$?

What is the unit digit of $(217)^{413} \times (819)^{547} \times (414)^{624} \times (342)^{812} ?$

If $\frac{1}{\sqrt{a}} - \frac{1}{\sqrt{b}} = 0$,then the value of $\frac{1}{a} + \frac{1}{b}$ is

If $\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right) \ldots\left(1-\frac{1}{70}\right)=\frac{x}{70},$ then what is the value of $x ?$

$\frac{5}{6} \div \frac{6}{7} \times ? - \frac{8}{9} \div 1 \frac{3}{5} + \frac{3}{4} \times 3 \frac{1}{3} = 2 \frac{7}{9}$

$1+1 \div\left\{1+1 \div\left(1-\frac{1}{3}\right)\right\}=?$