In how many ways 7 persons can be selected from 5 indian, 4 british and 2 chinise, if atleast 2 are to be selected from each country.

Hi Rajat,

The answer is :

At least 2 persons have to be slected form each country so :

ways of selecting 2 persons from 5 indians is ⁵C₂

ways of selecting 2 persons from 4 british is ⁴C₂

ways of selecting 2 persons from 2 chinese is ²C₂ 

Thus ways of slecting 6 persons form entire group is   ⁵C₂ * ⁴C₂ * ²C₂ 

Now 1 person has to be selected from remaing 3 Indians and 2 british and 0 chinese

possible way of selceting 1 person is ⁵C₁

Thus final answer to select 7 persons is ⁵C₂ * ⁴C₂ * ²C₂ *  ⁵C₁

Please feel free to ask as many questions you have.

Puneet

hey I have answer booklet (not solution). And in it answer given is "100".

My one frnd has suggested me the solution as:

you have to choose two chinese forced, at least two british and two indians, and one between british or indian. so you have

1*⁴C2*⁴C₂*(3+2)=180    the last term: 3 indians+2 british....

But its also wrong