Question

A lady gives a dinner party to six quests. The number of ways in which they may be selected from among ten friends, if two of the friends will not attend the party together is

Answer 1

Answer:

10c6 / 2!

Step-by-step explanation:

10 * 9 * 8 * 7 * 6 * 5/6 * 5 *4 *3 *2 *1 * 2!

5 * 3 * 7

105