In part (e) The path A-X-N-B cannot be considered as shortest path. since after reaching X we have to go one step back horizontally to reach N. so, path A-X-N-B is taking a step more than the path A-N-X-B. Please correct me if I am wrong. Reply

I think there is a mistake in part b question.

Please elucidate? What’s the mistake?

regards

J

Isn’t it the number of ways from A to X and X to B are 7C2 and 6C3 ways respectively ?

Sorry, My mistake. I was looking at A to X and X to B instead of P to X and X to Q.

A mistake in part d, i guess

In part (e)

The path A-X-N-B cannot be considered as shortest path. since after reaching X we have to go one step back horizontally to reach N. so, path A-X-N-B is taking a step more than the path A-N-X-B.

Please correct me if I am wrong.

Sorry I got it . No need to explain.