# Average Questions

**FACTS AND FORMULAE FOR AVERAGE QUESTIONS**

**1**. Average =

**2**. Suppose a man covers a certain distance x kmph and an equal distance at y kmph. Then, the average speed during the whole journey isKmph

A) 0 | B) -1 |

C) 1 | D) none of these |

Explanation:

Average of 20 numbers = 0.

Sum of 20 numbers = (0 * 20) = 0.

It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (- a).

A) 4991 | B) 5467 |

C) 5987 | D) 6453 |

Explanation:

Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009.

Required sale = Rs.[(6500 x 6) - 34009]

= Rs. (39000 - 34009)

= Rs. 4991.

A) 4 | B) 8 |

C) 12 | D) 16 |

Explanation:

Let the numbers be x, x + 2, x + 4, x + 6 and x + 8.

Then [x + (x + 2) + (x + 4) + (x + 6) + (x + 8) ] / 5 = 61.

or 5x + 20 = 305 or x = 57.

So, required difference = (57 + 8) - 57 = 8

A) 70 kg | B) 75 kg |

C) 80 kg | D) 85 kg |

Explanation:

Total weight increased = (8 x 2.5) kg = 20 kg.

Weight of new person = (65 + 20) kg = 85 kg.