- #1

MathMan2022

- 12

- 1

- Homework Statement
- Lets image following problem.

We have a group of 7 students, where you are suppose to select a team of 1 boy and two girls. And that 5 of the team 3 girls and 2 are boys. What is the probability that a team consist of one boy and 2 girls?

- Relevant Equations
- k*l = number of combinations

K(n,r) = n!/r!*(n-r)!

I know this problem can be done as follows.

P(1 boy and two girls) = (C(2,1)*C(5,2))/C(7,3) = 20/35

My question can this be written as probility fractions? Meaning

Lets say if that (2/5*3/7+1/2*1/7)/(3/7) But that doesn't give same result? what am I doing wrong?

P(1 boy and two girls) = (C(2,1)*C(5,2))/C(7,3) = 20/35

My question can this be written as probility fractions? Meaning

Lets say if that (2/5*3/7+1/2*1/7)/(3/7) But that doesn't give same result? what am I doing wrong?