Number System


  1. The simplified value of
    1 −
    1
    1 −
    1
    1 −
    1
    ........ 1 −
    1
    1 −
    1
    34599100









  1. View Hint View Answer Discuss in Forum

    2
    ×
    3
    ×
    4
    ×......×
    98
    ×
    98
    34599100


    =
    2
    =
    1
    10050

    Correct Option: C

    2
    ×
    3
    ×
    4
    ×......×
    98
    ×
    98
    34599100


    =
    2
    =
    1
    10050


  1. The sum of the squares of two positive numbers is 100 and difference of their squares is 28. Find the sum of the numbers :









  1. View Hint View Answer Discuss in Forum

    According to question
    x2 + y2 = 100 ...(i)
    x2 − y2 = 28 ...(ii)
    Adding both the equations
    x2 + y2
    x2 − y2
    -----------
    2x2    128
    ⇒  x2 = 64    ∴  x = 8
    From the equation (i)
    y2 = 100 − 64    ∴  y = 6
    So, x + y = 8 + 6 = 14

    Correct Option: C

    According to question
    x2 + y2 = 100 ...(i)
    x2 − y2 = 28 ...(ii)
    Adding both the equations
    x2 + y2
    x2 − y2
    -----------
    2x2    128
    ⇒  x2 = 64    ∴  x = 8
    From the equation (i)
    y2 = 100 − 64    ∴  y = 6
    So, x + y = 8 + 6 = 14



  1. The numbers 1, 3, 5,7 .., 99 and128 are multiplied together. The number of zeros at the end of the product must be :









  1. View Hint View Answer Discuss in Forum

    In 2m × 5n, the number of zeros
    = n when m ≥ n
    = m when m < n
    Here, 128 = 27
    In 1 × 3 × 5 × 7 × ... × 99 multiples of 5 are 5, 15, 25, 35, 45, 55, 65, 75, 85, 95 (= 510)
    Clearly, 7 zeros will be found in the product.

    Correct Option: C

    In 2m × 5n, the number of zeros
    = n when m ≥ n
    = m when m < n
    Here, 128 = 27
    In 1 × 3 × 5 × 7 × ... × 99 multiples of 5 are 5, 15, 25, 35, 45, 55, 65, 75, 85, 95 (= 510)
    Clearly, 7 zeros will be found in the product.