SOLUTION: Two representatives are chosen from random from a group of 80 students that has 40 boys and 40 girls. What is the probability that both representatives are girls.
a. 20/79
b.
Algebra.Com
Question 611373: Two representatives are chosen from random from a group of 80 students that has 40 boys and 40 girls. What is the probability that both representatives are girls.
a. 20/79
b. 1/4
c. 39/158
d. 39/160
I think the answer is b is that correct?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
Answer b would be correct if you put the first one you picked back into the mix and then picked the second one allowing for the possibility that both choices would be the same person. Since that is a ludicrous idea for choosing two representatives, we have to assume non-replacement, and therefore dependent probability.
The probability of the first selection being a girl is indeed 1/2, but once a girl has been selected for the first representative, there are now only 39 girls left in a total population of 79 students. Hence, the probability of picking a girl on the second draw is reduced to 39/79. The probablity of both events, i.e. girl on first draw and girl on second draw is the product of the two probabilities, 1/2 times 39/79. You can do your own arithmetic.
John
My calculator said it, I believe it, that settles it
RELATED QUESTIONS
two representatives are chosen at random from a group of 160 students that has 80 girls... (answered by ewatrrr)
two representatives are chosen at random from a group of 180 students that has 90 girls... (answered by stanbon)
Two representatives are chosen at random from a group of 180 students that has 90 girls... (answered by ikleyn)
Two students from a class of 12 boys and 8 girls are chosen at random. What is the... (answered by FrankM)
A class consists of 10 boys and 15 girls. Two of the boys and five of the girls are... (answered by rothauserc)
From a group of 6 boys and 8 girls, a delegation of 10 students is chosen at random. How... (answered by jim_thompson5910)
Two students are selected at random from a class of 8 boys and 9 girls. what is the... (answered by checkley79)
In a group of 16 students there are 10 girls and 6 boys. determine the number of ways... (answered by ikleyn)
From a group of 10 boys and 12 girls, a committee of 4 students is chosen at random. What (answered by ewatrrr)
