Two-way tables can be used to display information relating to several different options and categories.

The following table shows the numbers of right and left-handed children in a school year group of 70 children.

Boys | Girls | Total | |
---|---|---|---|

Right | 24 | 32 | 56 |

Left | 4 | 10 | 14 |

Total | 28 | 42 | 70 |

Notice how the totals add up in both directions.

There are 56 right-handed children.

There are 32 right-handed girls.

The probability that a child chosen at random is a right handed girl is 32/70 = **16/35**