The value of $25 - 5[2 + 3\{2 - 2(5 - 3) + 5\} - 10] \div 4$ is

The simplification of $\left[\frac{1}{2}+\frac{1}{2}\left\{\frac{3}{4}-\frac{1}{2}\left(\frac{7}{8}-\frac{3}{4}\right)\right\}\right]$ yields

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

$A$ person was to multiply a fraction by $\frac{6}{7}$. Instead,he divided the fraction by $\frac{6}{7}$ and got an answer which exceeds the correct answer by $\frac{1}{7}$. The correct answer is:

$(7.5 \times 7.5 + 37.5 + 2.5 \times 2.5)$ is equal to

If $a = \sqrt{2} + 1$ and $b = \sqrt{2} - 1,$ then the value of $\frac{1}{a + 1} + \frac{1}{b + 1}$ will be