# Number of pairs in SQL

## Question

Suppose you're given the following table showing sock inventory. Each row represents an individual sock (with the same style/size), and the 'color' column denotes the sock's color. **Given this information, write a SQL query to return the number of pairs (two socks with matching colors) that can be made from the inventory shown. Your result should be returned as a single integer number.**

Table: **color_sorting**

sock_id | color |
---|---|

1 | red |

2 | blue |

3 | black |

4 | blue |

5 | red |

6 | black |

7 | red |

8 | white |

9 | red |

10 | blue |

11 | red |

12 | red |

You can view/query the data in an interactive SQL fiddle here.