Question

,MEDAL GIVEN!!!
A couple plans to have four children. Using a tree diagram , obtain the sample space. Then, find the probability that the family has no boys

Answer 1

Using the tree, we get the sample space:

{b,b,b,b}
{b,b,b,g}
{b,b,g,b}
{b,b,g,g}
{b,g,b,b}
{b,g,b,g}
{b,g,g,b}
{b,g,g,g}

{g,b,b,b}
{g,b,b,g}
{g,b,g,b}
{g,b,g,g}
{g,g,b,b}
{g,g,b,g}
{g,g,g,b}
{g,g,g,g}

So for instance {b,g,g,b} means that the couple had a boy, girl, girl, and then a boy (in that order).

Note: recall, the sample space is the set of ALL possible outcomes.

Answer 2

So the probability of the couple having AT LEAST 3 boys is 5/16 which is 0.3125 in decimal form which gives a 31.25% chance.