One year ago liz was three times as old as her brother jack. in two years she'll be only twice as old as jack. how old are liz a
1 answer:
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Answer:
a) {GGG, GGB, GBG, BGG, BBG, BGB, GBB, BBB}
b) {0,1,2,3}
c)
d)
Step-by-step explanation:
We are given the following in the question:
Suppose a couple planned to have three children. Let X be the number of girls the couple has.
a) possible arrangements of girls and boys
Sample space:
{GGG, GGB, GBG, BGG, BBG, BGB, GBB, BBB}
b) sample space for X
X is the number of girls couple has. Thus, X can take the values 0, 1, 2 and 3 that is 0 girls, 1 girl, 2 girls and three girls from three children.
Sample space: {0,1,2,3}
c) probability that X=2
P(X=2)
That is we have to compute the probability that couple has exactly two girls.
Favorable outcome: {GGB, GBG, BGG}
d) probability that the couple have three boys.
Favorable outcome: {BBB}