What should come in place of the question mark $(?)$ in the following expression?
$(674.87 + 59.98) \div 35.02 = ?$

What is the value of $\frac{(941+149)^{2}+(941-149)^{2}}{(941 \times 941+149 \times 149)}$?

What should come in place of the question mark $(?)$ in the following equation?
$\sqrt{575} \div ? \times 14.98^{2} = 450$

What is the value of $\frac{(0.5)^{3}-(0.1)^{3}}{(0.5)^{2}+0.5 \times 0.1+(0.1)^{2}}?$

Simplify: $2 \div [2 + 2 \div \{2 + 2 \div (2 + 2 \div 3)\}]$

In a certain college,the number of girls is twice the number of boys. $\frac{1}{5}$ of the girls and $\frac{1}{8}$ of the boys took part in a social camp. What part of the total number of students took part in the camp?