# biology

posted by .

A couple has four children. What is the probability that there will be 2 boys and 2 girls? Assume that no outside forces influence the births.

• biology -

Here are the ways it can happen:
all boys, only one way.
bbbb
three boys, one girl, four ways:
bbbg
bbgb
bgbb
gbbb
2girls, two boys six ways.
ggbb
gbgb
gbbg
bggb
bgbg
bbgg
three g, one boy, same as 3b,one g four ways.
four girls
gggg one way.

so probaby of two girls, two boys..

= six/total ways=6/16= 3/8

## Similar Questions

1. ### help... probability

The Smith family has 4 children that are all girls. What is the probability that the next one will be a girl?
2. ### Math

Assume that the probability is 1/2 that a baby born is a boy. If a couple has two children, what is the probability that both are girls?
3. ### maths

Hi Can anyone help please: Suppose that the births of boys and girls can be modelled by rollling a fair die with 27 faces, 14 of which represent a boy and 13 represent a girl. 1. Using this model, choose the option that is closest …
4. ### maths

Hi Can anyone help please: Suppose that the births of boys and girls can be modelled by rollling a fair die with 27 faces, 14 of which represent a boy and 13 represent a girl. 1. Using this model, choose the option that is closest …
5. ### math

A couple intends to have four children. Assume that having a boy and girl is equally likely event. a) List sample space b) Find the probability that couple has two boys and two girls; c) Find the probability that couple has at least …
6. ### statistics

3. A couple is planning on having four children. Assume that the probabilities of the man fathering a boy or a girl are .50 and .50, respectively. What is the probability that a. exactly two will be boys, b. fewer than two will be …
7. ### statistics

Define each of the following probability terms for the scenario of determining the probability that when a couple has 3 children, they will have exactly 2 boys. Assume that boys and girls are equally likely and that the gender of any …
8. ### stats

Find the probability of at least 2 girls in 10 births. Assume that male and female births are equally likely and that the births are independent events.
9. ### math (stats)

Enter your answers as decimals or fractions, rather than percents. In a family with 7 children what is the probability of having 4 boys and then 3 girls, in that order?
10. ### Maths

It is assumed that when children are born they are equally likely to be boys or girls.What is the probability that a family of four children contains (a) three boys and one girl (b) two boys and two girls

More Similar Questions