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

What is the smallest $6$-digit number that is completely divisible by $108$?

$A$ number is of two digits. The position of digits is interchanged and the new number is added to the original number. The resultant number will always be divisible by

The sum and product of two numbers are $12$ and $35$ respectively. The sum of their reciprocals will be

$\frac{(0.188+0.077)^{2}+(0.188-0.077)^{2}}{0.188 \times 0.188+0.077 \times 0.077} = ?$

$P, Q$ and $R$ scored $581$ runs such that $4$ times $P$'s runs are equal to $5$ times $Q$'s runs,which are equal to $7$ times $R$'s runs. Find the difference between $P$'s runs and $R$'s runs.