
Viktoria D. answered 11/01/19
Science, Math, and Russian Tutor
There are a few ways of looking at this problem. First, you can consider each outcome individually. To get a boy as a first child is a probability of 1/2, as a second child is 1/2 and as a third child is 1/2 regardless of the other outcomes. To find the probability of all boys we multiply 0.5*0.5*0.5 = 0.125, or 1/8.
Another way of reasoning this out is listing all the possible outcomes (b=boy, g=girl) in order of how it happens, where the first letter means the first child.
bbb
bbg
bgb
gbb
ggg
ggb
gbg
bgg
From this you can see that all boys is one of 8 outcomes, so the answer is 1/8.