Question

The number of ways of selecting 3 girls and 3 boys out of 7 girls and 6 boys are

Answer 1

Answer:

10 + 6 + 3 + 1 = 20 ways to choose 3 boys out of six boys. 10 * 20 = 200 ways to pick 3 boys and 2 girls out of a pool of 6 boys and 5 girls.

Answer 2

$selecting \: 3 \: boys \: \\ we \: have \: to \: select \: 3 \: boys \: from \: 6 \: boys \\ here \: n = 6 \: and \: r = 3$

$number \: of \: ways = {n} _{c}r \\ = {6} _{c}3$

= 6! / 3!(6-3)!

= 6!/3!3!

=12

$selecting \: 3 \: girls \\ we \: have \: to \: select \: 3 \: girls \: from \: 7 \: girls \\ here \: n = 7\: and \: r = 3 \\ number \: of \: ways \: = n_{c}r \\ = 7_{c}3$

= 7! / 3!(7-3);

= 7!/3!4!

=14

Total no of ways

12*14

= 168

thanks