6. Talking about his neighbours, Ram says: "A is 5 times as old as B but his age is | 7 | of C's age. |

18 |

How much younger is B to C?

a. 27 years

b. 56 years

c. 83 years

d. Cannot be determined

**Answer:** c. 83 years

**Explanation:**

A's age = 5 times B's = 5B years

Also, A's age | = | 7 | of C's age |

18 |

∴ C's age | = | 18 | of A's age = | 18 | x 5B = | 90B | years |

7 | 7 | 7 |

A's age + B's age + C's age = 132 -------------- Given

∴ 5B + B + | 90B | = 132 years |

7 |

∴ 35B + 7B + 90B = 132 x 7 --------------- Multiply by 7 on both sides

∴ B = 7 years

C's age = | 90B | = 90 years |

7 |

a. 32 years

b. 36 years

c. 38 years

d. 40 years

**Answer:** d. 40 years

**Explanation:**

Present average age of the group = 36 years

Sum of present ages of all 4 children in the group = 36 x 4 = 144 years.

The youngest child is 6 years old, which means, the youngest was born 6 years ago.

So now, 6 years ago,

Sum of ages of all 4 children = 144 - (6 x 4) = 144 - 24 = 120 years

Since youngest one was just born, his age was 0.

So, now we should not include the youngest child in the group

So now, total number of children = 4-1=3

Average age of group at time birth of the youngest child | = | Sum of ages of children |

Number of children |

∴ Average age of group at time birth of the youngest child | = | 120 | = 40 years |

3 |

a. 1 year

b. 2 years

c. 3 years

d. 4 years

**Answer:** c. 3 years

**Explanation:**

4 years back,

Average age of family = 19 years

Sum or Total of all ages of all 4 family members = 19 x 4 = 76 years

In present day, that means after 4 years,

Sum or Total of present ages of these 4 family members = 76 + (4 x 4) = 92 years.

Let the child's present age be K years.

Now family is of 5 members (because a child has been added some years back)

Present average age of family | = | Sum of present ages of 4 members + Child's present age |

5 |

Average remains same as it was 4 years back

∴ 19 | = | 92+K |

5 |

a. 26 years

b. 30 years

c. 34 years

d. 36 years

**Answer:** d. 36 years

i. The average age of two boys is five and a half years.

ii. If we find the average age of two boys and the father, it is 3 years more than the average age of boys with mother.

Find the age of father and mother.

a. 35 years and 32 years

b. 37 years and 28 years

c. 47 years and 38 years

d. 50 years and 41 years

**Answer:** a. 35 years and 32 years