CAT 1991 — QA Question 18
Permutation & CombinationEasy
What is the total number of ways to reach A to B in the network given?
Answer & solution
Correct answer: 16
- A
12
16
- C
20
- D
22
Solution
To go from A to B, we need to pass through 3 levels of nodes.
Number of ways of goind from A to any of the level 1 node = 4
Number of ways of goind from any of the level 1 node to any of the level 2 node = 2
Number of ways of goind from any of the level 2 node to B = 2
Total number of ways to reach A to B = 4 × 2 × 2 × 1 = 16.
Hence, option (b).