Question

In how many ways can a group of 5 boys and 4 girls be selected from the group of 7 boys and 8 girls?
Select one:
a. 7C2*8C6
b. 7C5*804
O C. 7C3*8C2
O d. 704*8C3​

Answer 1

Answer:

ANSWER

Total number of girls in the group =4

Total number of boys in the group =7

Probability of selecting atleast one boy and one girl =?

By considering following ways we can select

i) 1 girls +4 boys ⇒

4

C

1

×

7

C

4

ii) 2 girls +3 boys ⇒

4

C

2

×

7

C

3

iii) 3 girls +2 boys ⇒

4

C

3

×

7

C

2

iv) 4 girls +1 boy ⇒

4

C

4

×

7

C

1

Total number of ways =(

4

C

1

×

7

C

4

)+(

4

C

2

×

7

C

3

)+(

4

C

3

×

7

C

2

)+(

4

C

4

×

7

C

1

)

=140+210+84+7

=441