The power of the composite lens made of two thin lenses of focal lengths $f_1$ and $f_2$ placed in contact will be:

$\frac{(f_1+f_2)}{f_1f_2}$ $\frac{f_1f_2}{(f_1+f_2)}$ $\sqrt{f_1f_2}$ $\frac{1}{\sqrt{f_1f_2}}$

$\frac{(f_1+f_2)}{f_1f_2}$

The correct answer is Option (1) → $\frac{(f_1+f_2)}{f_1f_2}$