#NPTEL

Question

Comments

Is there a restriction on the type of moves you can make?

If you can only make right and up moves, the answer will be $\frac{10!}{5!\times5!}$

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how...I m not getting it

Answer 1

To reach the top, you'll have to take 5 rights (R) and 5 upward (U) movements. (This is regardless of whatever path you might take).

Trying all permutations of 5 R and 5 U will give you the desired answer - which is $\frac{(5 + 5)!}{5! \times 5!}$

Comments

what about when we can't cross the diagonal?