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If a * b = 2a - 3b + ab, then 3 * 5 + 5 * 3 is equal to?

A. 22

B. 24

C. 26

D. 28

Answer: Option A

Solution (By Examveda Team)

$$\eqalign{ & 3*5 + 5*3 \cr & \Rightarrow 3*5 = 2 \times 3 - 3 \times 5 + 3 \times 5 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 6 - 15 + 15 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 6 \cr & \Rightarrow 5*3 = 2 \times 5 - 3 \times 3 + 3 \times 5 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 10 - 9 + 15 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 16 \cr & \therefore 3*5 + 5*3 \cr & \Rightarrow 6 + 16 = 22 \cr} $$

This Question Belongs to Arithmetic Ability >> Algebra

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Comments (3)

  1. Zahid Ali
    Zahid Ali:
    8 months ago

    To solve the problem, we first need to understand the operation defined by ( a * b = 2a + 3b + ab ). We are asked to find the value of ( 3 * 5 + 5 * 3 ).

    Let's break it down step by step.

    ### Step 1: Compute ( 3 * 5 )
    Using the definition of the operation:
    [
    3 * 5 = 2(3) + 3(5) + (3)(5)
    ]
    Calculate each term:
    [
    2(3) = 6
    3(5) = 15
    (3)(5) = 15
    ]
    Now, add them together:
    [
    3 * 5 = 6 + 15 + 15 = 36
    ]

    ### Step 2: Compute ( 5 * 3 )
    Using the definition of the operation:
    [
    5 * 3 = 2(5) + 3(3) + (5)(3)
    ]
    Calculate each term:
    [
    2(5) = 10
    3(3) = 9
    (5)(3) = 15
    ]
    Now, add them together:
    [
    5 * 3 = 10 + 9 + 15 = 34
    ]

    ### Step 3: Add the Results
    Now, add the results of ( 3 * 5 ) and ( 5 * 3 ):
    [
    3 * 5 + 5 * 3 = 36 + 34 = 70
    ]

    However, none of the provided options (A) 22, (B) 24, (C) 26, (D) 28 match the result of 70. This suggests there might be a mistake in the problem statement or the provided options.

    But let's double-check the calculations to ensure there's no error.

    ### Re-evaluating the Calculations
    Recompute ( 3 * 5 ):
    [
    3 * 5 = 2(3) + 3(5) + (3)(5) = 6 + 15 + 15 = 36
    ]
    Recompute ( 5 * 3 ):
    [
    5 * 3 = 2(5) + 3(3) + (5)(3) = 10 + 9 + 15 = 34
    ]
    Adding them:
    [
    36 + 34 = 70
    ]
    The calculations are correct, and the result is indeed 70.

    Given that none of the provided options match 70, it's possible that there's a typo in the problem or the options. However, based on the given operation and calculations, the correct answer should be 70.

    **Final Answer:** 70 (Note: This does not match any of the provided options.)

  2. Habib Khan
    Habib Khan:
    3 years ago

    when we will find 3*5
    here a=3, b=5,putting in equation given we will find value of 3*5
    when we will find 5*3
    here a=5, b=3, putting in equation given we will find value of 5*3
    after that we will add them

  3. Nisar Shoaib43
    Nisar Shoaib43:
    6 years ago

    what does mean by* in question

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