Question

Harry walks from his
house at A to his
office at B. by taking
the shortest path.
Find in how many
ways Harry can go
from A to B moving
only Up or Right at
every intersection of
roads.
8
A​

Answer 1

He will go from A to B in 10 different ways.

Explanation:

• As the question statement says that Pat should only go UP and RIGHT by taking the shortest route.
• Namely thrice UP and twice RIGHT.
• So a combination of UUURR shows that 5 letters out of which there are 3 identical U's and identical R's.
• The probability is 5!/3!2!=10.
• As there are 4 streets and 3 avenues therefore the number of paths taken by pt would be 10.