Question

NO LINKS!! URGENT HELP PLEASE!!!

A family has 3 children. It is equally likely (50%) that they could have a boy or a girl. What is the probability that they have two girls, and then a boy? Use a tree diagram to find the probability (hint: your first two options should be a boy or a girl, then it will branch off for the second child, then again for the third child).

Answer 1

1/8 or 0.125 (12.5%).

Explanation:

Using the tree diagram, we can see that there are 8 possible outcomes for the gender of the three children: BBB, BBG, BGB, BGG, GBB, GBG, GGB, GGG. Since each outcome is equally likely, the probability of any one outcome is 1/8.

The outcome we are interested in is GGB, which has a probability of 1/8. Therefore, the probability that the family has two girls, and then a boy is 1/8 or 0.125 (12.5%).

Answer 2

The probability that the couple have two girls and then a boy is 1/8 (12.5%).

Explanation:

Tree diagrams show probabilities for sequences of two or more independent events.

To draw a tree diagram showing the given information:

• There are three trials - 'Child 1', 'Child 2' and 'Child 3'.

• Each trial has two possible results - ‘girl’ and ‘boy’.

• The probability of having a girl is 1/2.

• The probability of having a boy is 1/2.

See the attachment for the tree diagram.

To find the probability that the couple have two girls and then a boy, multiply along the branches representing those events.

Therefore, the probability that the couple have two girls and then a boy is:

`\sf P(girl)\;and\;P(girl)\;and\;P(boy)=(1)/(2) * (1)/(2) * (1)/(2)=(1)/(8)=12.5\%`