Mathematical operation and symbol notation


Direction: Correct the following equations by interchanging the two signs.

  1. 15 ÷ 9 x 3 - 74 + 2 = 5
    1. + and -
    2. ÷ and x
    3. + and ÷
    4. - and ÷
    5. None of the these

  1. View Hint View Answer Discuss in Forum

    Lets try all options one by one.

    Correct Option: C

    If we interchanges signs '+' and '÷', then the equation changes into
    15 + 9 x 3 - 74 ÷ 2 = 15 + 27 - 37 = 5


  1. 51 ÷ 3 x 12 - 6 + 3 = 201
    1. + and ÷
    2. - and +
    3. x and ÷
    4. - and x
    5. None of these

  1. View Hint View Answer Discuss in Forum

    Lets try all options one by one.

    Correct Option: E

    None of the interchange is applicable in the equation to produce number 201



  1. 16 + 4 ÷ 2 - 21 x 7 = 21
    1. + and -
    2. + and x
    3. - and ÷
    4. x and ÷
    5. None of these

  1. View Hint View Answer Discuss in Forum

    Lets try all options one by one.

    Correct Option: D

    If we interchange the signs 'x' and '÷' the equation becomes
    16 + 4 x 2 - 21 ÷ 7 = 16 + 8 - 3 = 21


  1. 32 x 2 2 ÷ (62 - 9) + 12 = 33
    1. - and ÷
    2. + and x
    3. x and ÷
    4. + and -

  1. View Hint View Answer Discuss in Forum

    Lets try all options one by one.

    Correct Option: A

    If we interchange symbols '-' and '÷', the equation becomes
    9 x 4 - (36 ÷ 9) + 1
    = 9 x 4 - 36/9 + 1
    = 36 - 4 + 1
    = 33



Direction: In the following questions, which one of the four interchanges in signs and numbers would make the given equation correct?

  1. 4 x 6 - 2 = 14
    1. x to ÷, 2 and 4
    2. - to +, 2 and 6
    3. x to +, 4 and 8
    4. - to ÷, 2 and 6

  1. View Hint View Answer Discuss in Forum

    Interchange '-' to '+' and 2 to 6 and try

    Correct Option: B

    On interchanging '-' to '+' and 2 to 6
    4 x 2 + 6 = 14
    ⇒ 8 + 6 = 14
    ⇒ 14 = 14