Question

There are 7 girls and 2 boys. A team of 4 persons must be chosen with at least 1 boy on the team. In how many ways can this be done.

Answer 1

Use permutations

Answer 2

@ajprincess

Answer 3

Consider it a team of 3 from 7 girls and 1 boy (the other one). That's 8 choose 3. Unfortunately, changing the problem has an effect: if we choose the other boy we have issues. Now let's separate it into two possibilities: one boy is chosen, then it's 7 choose 3 (times two, we have two possible boys in that scenario) or both boys are picked and it's 7 choose 2 (times one, both boys are accounted for). Add these and you have your answer.

Answer 4

nCr= n!/((n-r)!*r!) \[\Large nCr=\frac{n!}{((n-r)*r!)r!}\]
Use that ^

Answer 5

ok

Answer 6

Thank you sir