Question

4 members form a group out of total 8 members. 
(i) In how many ways it is possible to make the group if two particular members must be included.
(ii) In how many ways it is possible to make the group if two particular members must not be included? ​

Answer 1

Answer:

In how many ways it is possible to make the group if two particular members must be included.

(ii) In how many ways it is possible to make the group if two particular members m

Answer 2

Answer:

I). if two particular members must be included:

no. of ways of including two particular member = 1

now we have to choose two out of remaining 6 members

no. of ways = 6C2 = 6!/4!2!

= 5*6/2

= 15

total number of ways = 15*1 = 15

ii). if two members must not be included:

then we have to choose four member out of remaining 6 members

no. of ways = 6C4 = 6!/4!2!

= 5*6/2

= 15