Question

Find the probability of a couple having at least 1 girl among 4 children. Assume that boys and girls are

equally likely and that the gender of a child is independent of the gender of any brothers or sisters.

Answer 1

15/16 (93.75%)

Explanation:

List of Possible Combinations:

BBBB, BBBG, BBGB, BBGG, BGBB, BGBG, BGGB, BGGG, GBBB, GBBG, GBGB, GBGG, GGBB, GGBG, GGGB, GGGG

As you can see, only 1 out of 16 of the possible combinations is all boys. This means that the chance of at least 1 girl among the 4 children is 15 out of 16 (15/16) or 93.75%