A man has 7 friends, 4 of them are ladies and 3 are men. His wife also has 7 friends, 3 of them are ladies and 4 are men. Assume and have no common friends. Then the total number of ways in which and together can throw a party inviting 3 ladies and 3 men, so that 3 friends of each of and are in this party, is :
- (A)484
- (B)485✓ Correct
- (C)468
- (D)469
Answer: (B)
Solution
We want three ladies and three men at the party, with exactly three guests drawn from each host's own circle. Sorting by how the ladies divide between the two sides, the four workable cases contribute , , and ways, and together they give .
JEE Main · 2017 · 02 Apr 2017 · Offline · Single correct option