Difficulty: Medium
Correct Answer: 8
Explanation:
Let
n = original number of friends, so original share = 96/n.
After 4 drop
New number = n − 4; new share = 96/(n − 4). Increase per person = 4 ⇒ 96/(n − 4) − 96/n = 4.
Solve
96·(n − (n − 4)) / [n(n − 4)] = 4 ⇒ 96·4 / [n(n − 4)] = 4 n(n − 4) = 96 ⇒ n² − 4n − 96 = 0 ⇒ (n − 12)(n + 8) = 0 ⇒ n = 12. Attended = n − 4 = 8.
Discussion & Comments