Problems on Ages


  1. 20 years ago my age was 1/3 of what it is now. What is my present age ?









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    Let my present age be x years.
    ∵ x - 20 = x / 3

    Correct Option: A

    Let my present age be x years.
    ∵ x - 20 = x / 3
    ⇒ 3x - 60 = x
    ⇒ 2x = 60
    ∴ My present age = x = 30 years


  1. A 280 m long train crosses a platform which is three times of its length, in 6 min 40 s. What is the speed of the train ?









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    Length of the train = 280 m
    Length of the platform = 280 x 3 = 840 m
    Taken time = 6 min 40 s = (360 + 40) s = 400 s
    ∴ Required speed = Distance / Time

    Correct Option: C

    Length of the train = 280 m
    Length of the platform = 280 x 3 = 840 m
    Taken time = 6 min 40 s = (360 + 40) s = 400 s
    ∴ Required speed = Distance / Time = (840 + 280)/400
    = 1120/400 = 2.8 m/s



  1. The present ages of Reena and Usha are 24 and 36 yr. respectively . What was the ratio between the ages of Usha and Reena respectively 8 yr ago ?









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    Required ratio = (36 - 8)/(24 - 8)

    Correct Option: A

    Required ratio = (36 - 8)/(24 - 8) = 28/16 = 7 : 4


  1. The average age of 8 children of a family is 12 yr. If the age of 7 children are 12, 8, 14, 11, 9, 13 and 15 yr. then the age of 8th child will be ?









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    ∵ Total age of 8 children = 8 x 12 = 96 yr
    And total age of 7 children = 12 + 8 + 14 + 11 + 9 + 13 + 15 = 82

    Correct Option: B

    ∵ Total age of 8 children = 8 x 12 = 96 yr
    And total age of 7 children = 12 + 8 + 14 + 11 + 9 + 13 + 15 = 82
    ∴ The age of 8th child = 96 - 82 = 14 yr



  1. The ratio between the present ages of A and B is 4 : 5. If the ratio between their ages 4 yr hence become 14 : 17, Then what is B's age at present ?









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    Let the ages of A and B are 4N and 5N yr. respectively.
    According to the question,
    ∴ (4N + 4)/(5N + 4) = 14/17

    Correct Option: A

    Let the ages of A and B are 4N and 5N yr. respectively.
    According to the question,
    ∴ (4N + 4)/(5N + 4) = 14/17
    ⇒ 68N + 68 = 70N + 56
    ⇒ 2N = 12
    ⇒ N = 6
    Hence present age of B = 5 x 6 = 30 yr