Algebra - 3 girtls and 4 boys going for picnin

865

Soumyadeep Basu ·2013-02-18 08:02:47

Answer should be (B).
Total no. of picnics is 21. Out of them, only one girl goes in 3C1 X 4C4=3 ways. Thus 3 dolls are given.
Exactly 2 girls go in 3C2 X 4C3=12 ways. Thus 12 X 2=24 dolls are given.
Exactly 3 girls go in 3C3 X 4C2=6 ways. Thus 6 X 3=18 dolls are given.
Total no. of dolls given is 3+24+18=45.

UP 2 DOWN 0
Post on FacebookPost anonymously?

1057

Ketan Chandak ·2013-02-18 04:51:34

⁷C₅=21.

UP 0 DOWN 1
Ketan Chandak sorry..i found out the no of picnics...the rest is written below.. :P
Upvote·0· Reply ·2013-02-19 22:08:57
Post on FacebookPost anonymously?

66

Sourup Nag ·2013-02-19 19:16:46

The answer is 45

UP 0 DOWN 0
Post on FacebookPost anonymously?

1357

Manish Shankar ·2013-02-19 23:35:20

Yup the answer is 45

Good work Soumyadeep

UP 0 DOWN 0
Post on FacebookPost anonymously?

66

Sourup Nag ·2013-02-20 09:46:55

I have approached the question in a different way:

1st let us fix one girl and find out how many dolls she could get

Case 1: She goes with 2 girls and 2 boys and that can happen in 4C2 ways i.e. 6 ways

Case 2: She goes with 1 girl and 3 boys and that can happen in 2C1*4C3 i.e. 8 ways

Case 3: She goes with 4 boys and that can happen in 1 way only.

Hence the no of possible ways in which she can go/get a doll = 6+8+1 = 15.

As there are 3 girls in the group, the total no. of dolls the girls have got is 15*3 = 45

UP 0 DOWN 0
Post on FacebookPost anonymously?

3 girtls and 4 boys going for picnin

5 Answers

Your Answer

Similar Questions

3 girtls and 4 boys going for picnin

5 Answers

Your Answer

Add Image

Similar Questions