In-the-diagram-it-is-possible-to-travel-only-along-an-edge-in-the-direction-indicated-by-the-arrow-How-many-different-routes-from-A-to-B-are-there-in-all-

Question Number 16936 by Tinkutara last updated on 28/Jun/17

In the diagram, it is possible to travel

only along an edge in the direction

indicated by the arrow . How many

different routes from A to B are there

in all ?

Commented by Tinkutara last updated on 28/Jun/17

Commented by ajfour last updated on 28/Jun/17

N = (1 \times 3) + (2 \times 1 \times 3) + (2 \times 1)

= 3 + 6 + 2 = 11 .

Commented by Tinkutara last updated on 28/Jun/17

Please explain .

Commented by ajfour last updated on 28/Jun/17

(A \to Y) \times (Y \to B)

+ (A \to X) \times (X \to B)

+ (A \to X) \times (X \to Y) \times (Y \to B)

= 1 \times 3 + 2 \times 1 + 2 \times 1 \times 3 = 11 .

Commented by Tinkutara last updated on 29/Jun/17

Thanks Sir!