# Quantitative Ability (Part 3 of 9)

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Directions: Answer these questions on the basis of the information given below:

Let S be the set of all pairs (i, j) where 1 < i < j < n and n > 4. Any two distinct members of S are called “friends” if they have one constituent of the pairs in common and “enemies” otherwise. For example, if n = 4, then S = { (1,2) (1,3) , (1,4) , (2,3) , (2,4) , (3,4) ,} . Here (1,2) , and (1,3) are friends (1,2) , and (2,3) are also friends, but (1,4) and (2,3) are enemies.

- For general n, how many enemies will each member of Shave?
- (n2 − 7n + 14)
- n − 3
- (n2 − 3n − 2)
- 2n − 7
- (n2 − 5n + 6)

Answer: e

- For general n, consider any two members of S that are friends. How many other members of S will be common friends of both these members?
- (n2 − 7n + 16)
- (n2 − 5n + 8)
- 2n − 6
- n (n − 3)
- n − 2

Answer: e