When Hanako who can walk 15 m with ten steps for ten seconds advances by a method "going forth by three steps and going back by two steps", how many seconds does she take to advance 15m ?
It shall take one second for one step of going back and forth.
It shall take one second for one step of going back and forth.
Answer
38 seconds
Solution
As it takes one second for one step, Hanako goes forth one step in five seconds according to this method of movement.
Hanako goes forth seven steps in 35 seconds.
After seven steps, Hanako goes forth three steps with this method and she can reach 15 m by in total ten steps (seven plus three).
The time of proceeding 15 m is 35 + 3 = 38 seconds.
