Each member of a club contributes as much rupees and as much paise as the number of members of the club. If the total contribution is Rs. 2525, then the number of members of the club is:

Let the total member be x.
x member contribute is Rs. x and each member also contributes x paise.
So total rupees is
x member Rs. x = Rs. x²
x member Rs. x paise $$ = \frac{{x.x}}{{100}}$$
Total rupees is
$$\eqalign{ & {x^2} + \frac{{{x^2}}}{{100}} = 2525 \cr & 101{x^2} = 2525 \times 100 \cr & 101{x^2} = 101 \times 25 \times 100 \cr & \boxed{x = 50} \cr} $$