Numerical Ability


  1. A couple has 2 children. The probability that both children are boys if the older one is a boy is
    1. 1/4
    2. 1/3
    3. 1/2
    4. 1

  1. View Hint View Answer Discuss in Forum

    The probability of the second child being a boy is independent of the first child. Therefore, the required probability will be 1/2.

    Correct Option: C

    The probability of the second child being a boy is independent of the first child. Therefore, the required probability will be 1/2.


  1. M and N start from the same location. M travels 10 km East and then 10 km North-East. N travels 5 km South and then 4 km South-East. What is the shortest distance (in km) between M and N at the end of their travel.
    1. 18.60
    2. 22.50
    3. 20.61
    4. 25.00

  1. View Hint View Answer Discuss in Forum

    From the given data, the following diagram is possible

    cos 45° =
    DE
    4

    DE = cos45° × 4 = 2.828 km
    sin 45° =
    EN
    4

    EN = sin 45° × 4 = 2.828 km
    sin 45° =
    EN
    4

    EN = sin 45° × 4 = 2.828 km
    CN = NE + CE = 2.828 + 5 = 7.828 km
    CB = AB – AC = 10 – 2.828 = 7.171 km
    (NB)² = (NC)² + (BC)²
    = (7.828)² + (7.171)²
    ∴ NB = √(7.828)² + (7.171)²
    = 10.616 km
    ∴ NM = NB + BM = 10.616 + 10
    = 20.61 km

    Correct Option: C

    From the given data, the following diagram is possible

    cos 45° =
    DE
    4

    DE = cos45° × 4 = 2.828 km
    sin 45° =
    EN
    4

    EN = sin 45° × 4 = 2.828 km
    sin 45° =
    EN
    4

    EN = sin 45° × 4 = 2.828 km
    CN = NE + CE = 2.828 + 5 = 7.828 km
    CB = AB – AC = 10 – 2.828 = 7.171 km
    (NB)² = (NC)² + (BC)²
    = (7.828)² + (7.171)²
    ∴ NB = √(7.828)² + (7.171)²
    = 10.616 km
    ∴ NM = NB + BM = 10.616 + 10
    = 20.61 km



  1. Two and a quarter hours back, when seen in a mirror, the reflection of a wall clock without number markings seemed to show 1:30. What is the actual current time shown by the clock?
    1. 8:15
    2. 11 :15
    3. 12:15
    4. 12:45

  1. View Hint View Answer Discuss in Forum


    So present time = 10:30 + 2:15
    = 12:45

    Correct Option: D


    So present time = 10:30 + 2:15
    = 12:45


  1. A window is made up of a square portion and an equilateral triangle portion above it. The base of the triangular portion coincides with the upper side of the square. If the perimeter of the window is 6 m, the area of the window in m² is
    1. 1.43
    2. 2.06
    3. 2.68
    4. 2.88

  1. View Hint View Answer Discuss in Forum

    The possible window will be as follows:

    Perimeter of window = 5x = 6m
    x = 1.2 m
    So area of window = Area of triangle + Area of square

    =
    3
    x² + x²
    4

    =
    3
    (1.2)² + (1.2)²
    4

    = 2.06 m²

    Correct Option: B

    The possible window will be as follows:

    Perimeter of window = 5x = 6m
    x = 1.2 m
    So area of window = Area of triangle + Area of square

    =
    3
    x² + x²
    4

    =
    3
    (1.2)² + (1.2)²
    4

    = 2.06 m²



  1. The volume of a sphere of diameter 1 unit is than the volume of a cube of side 1 unit.
    1. least
    2. less
    3. lesser
    4. low

  1. View Hint View Answer Discuss in Forum

    ‘Lesser than’ is apt because the sentence should be in comparative degree.

    Correct Option: B

    ‘Lesser than’ is apt because the sentence should be in comparative degree.