Creative Logic: Kevin is hiking on the trail and has to cross a rope bridge. He looks down at the raging river below and is suddenly very nervous. The bridge has 20 planks on it and every time he steps forwards five planks, he then steps backwards four planks. How many times must he do this to reach the other side?

40 times

Step-by-step explanation:

Given: Total planks = 20

By using integers, Steps forward is represented by +5, Steps backward s represented by  -4.

After first set of two steps ( one forward another backward), 5-4 =1 step forward is captured.

For 20 planks , we require 20 such sets, i.e. he will do this 2x 20 times i.e. 40 times.

Hence, he will do this 40 times to reach the other side.

ummm..i would say for both the answer is 1.