# Alligation or Mixture Questions

**FACTS AND FORMULAE FOR ALLIGATION OR MIXTURE QUESTIONS**

**I. Alligation :** It is the rule that enables us to find the ratio in which two or more ingredients at the given price must be mixed to produce a mixture of a desired price.

**II. Mean Price :** The cost price of a unit quantity of the mixture is called the mean price.

**III. Rule of Alligation :** Suppose Rs.x per unit be the price of first ingradient mixed with another ingradient (cheaper) of price Rs.y per unit to form a mixture whose mean price is Rs. z per unit, then

Quantity of cheaper : Quantity of dearer

= ( C.P of dearer - Mean Price ) : ( Mean Price - C. P of cheaper )

= ( x- z ) : ( z - y )

**IV.** Suppose a container contains x units of liquid from which y units are taken out and replaced by water. After operations , the quantity of pure liquid = $x{\left(1-\frac{y}{x}\right)}^{n}$ units.

A) 2 : 5 | B) 1 : 5 |

C) 2 : 3 | D) 2 : 1 |

A) 7 : 9 | B) 5 : 7 |

C) 15 : 13 | D) 9 : 11 |

A) 49 : 48 | B) 7 : 7 |

C) 8 : 6 | D) 3 : 4 |

A) 1 : 1 | B) 2 : 1 |

C) 26 : 9 | D) 9 : 26 |