At a metro station, a girl walks up a stationary escalator in time `t_1`. If she remains stationary on the escalator, then the escalator take her up in time `t_2`. The time taken by her to walk up on the moving escalator will be

Options

A. `(t_(1)+t_(2))//2`
B. `t_(1)t_(2)//(t_(2)-t_(1))`
C. `t_(1)t_(2)//(t_(2)+t_(1))`
D. `t_(1)-t_(2)`

Answer

C