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Probability Math Question?
A teacher has 18 boys and 17 girls in her class. In how many ways can she select 4 of the children to be in a play if she must select 2 boys and 2 girls.
Please show me some steps, I'm just not getting this assignment
1 Answer
- Anonymous6 years ago
It's a simple combinations problem. How many ways can she select two boys? That's just the number of combinations of 18 things taken 2 at a time, or 18C2.
The formula for nCk is n! / k! (n-k)!, so this is 18x17/2 = 153,
You can select 2 girls from 17 in 17x16/2 = 136 ways.
The final answer is the product of those two, 153 x 136 20808