Aptitude Overflow
0 votes
53 views

A man has nine friends, four boys and five girls. In how many ways can he invite them, if there have to be exactly three girls in the invitees?

  1. $320$
  2. $150$ 
  3. $80$
  4. $200$
asked in Quantitative Aptitude by (4.8k points) 38 103 167
recategorized by | 53 views

1 Answer

+2 votes
Best answer

No. Of combinations girls can be invited: 5C3 = 10

Now there are 5 possibilities.

1: no boy is invited: 4C0 =1 , combining it with combinations of girls 1 * 10 = 10

2: 1 boy is invited: 4C1 = 4, combining it with combinations of girls 4 * 10 = 40

3: 2 boys were invited: 4C2 = 6, 6 * 10= 60

4: 3 boys were invited : 4C3 = 4, 4 * 10 = 40

5: all boys were invited: 4C4 = 1, 1 * 10 = 10

So, total no of ways of inviting 3 girls = 10 + 40 + 60 + 40 + 10 = 160

So ,  Correct Answer is 160.

answered by (2.5k points) 1 8 29
selected by
What about the combination of 0 boys and 3 girls? 10 more will be added right, which is 150 + 10 = 160
right

Related questions

2,724 questions
1,003 answers
393 comments
31,401 users