How one can take economy forward | Prafull Billore

Which one is in forward bias

A frog walking in a narrow lane takes 5 leaps forward and 3 leaps backward, then again 5 leaps forward and 3 leaps backward, and so on. Each leap is 1 m long and requires 1 s . Determine how long the frog takes to fall in a pit 13 m away from the starting point.