According to the formula, if pipe A can comletely fils a tank in x hours and pipe B can comletely fill a tank in y hours, then the time taken by both pipes together to fill the tank is $\frac{\mathrm{xy}}{\mathrm{x}+\mathrm{y}}$ hours.

So, $\frac{120\times 130}{120+130}=\frac{15600}{250}=62.4 \mathrm{minutes}$

The tank will be filled by both the pipe when opened simultaneously in 62.4 minutes

Hence option C is correct