Question

A couple plans to have four children. Using a tree diagram , obtain the sample space. List the elements that make up the sample space. (Use "B" for "boy" and "G" for "girl.")
A. BBBG, BBGB, BBGG, BGBB, BGBG, BGGB, BGGG, GBBB, GBBG, GBGB, GBGG, GGBB, GGBG, GGGB

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

C. BBBB, BBB, BB, B

D. BBBB, BBBG, BBGG, BGGG, GGGG

Answer 1

Correct answer is B.

There are $2^4 = 16$ points in the sample space, so choices C and D are automatically out.
 
Choice A is out because there is a possibility to have all 4 boys, but BBBB is not in choice A.
   
So the answer is choice B