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Home Aptitude Linear Equation See What Others Are Saying!
  • Question
  • If 2 a + 3 b = 17 and 2 a + 2 - 3 b +1 = 5, then


  • Options
  • A. a = 2, b = 3
  • B. a = -2, b = 3
  • C. a = 2, b = -3
  • D. a = 3, b = 2

  • Correct Answer
  • a = 3, b = 2 

    Explanation

    Given, 2a + 3b = 17
    and 2a + 2 - 3b + 1 = 5
    ? 22 x 22 - 3b x 31 = 5
    ? 4.2a - 3.3b = 5
    Let 2a = x amd 3b = y
    Then, x + y = 17 ...(i)
    4x - 3y = 5 ...(ii)
    On multiplying Eq. (i) by 3 and adding to Eq (ii), we get
    3x + 3y = 51
    4x - 3y = 5
    ------------------
    7x = 56
    ? x = 8

    On putting the value of x in Eq. (i), we get
    8 + y = 17
    ? y = 9

    Now, 2a = x
    ? 2a = 8 (2)3
    ? 3b = y = 9
    ? 3b = 32
    ? b = 2
    Hence, a = 3 and b = 2


  • More questions

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      Aarti can do a piece of work in 6 days. In how many days will she complete three time of work of same type?

    • Options
    • A. 18 days
    • B. 21 days
    • C. 3 days
    • D. 6 days
    • Discuss
    • 2. 
      750.0003 ÷ 19.999 =?

    • Options
    • A. 49
    • B. 18
    • C. 22
    • D. 38
    • Discuss
    • 3. 
      105, 85, 60, 30, 0, - 45, - 90?

    • Options
    • A. 0
    • B. 85
    • C. -45
    • D. 60
    • Discuss
    • 4. 
      Let A = {1, 2, {3, 4}, 5}. Which of the following statements is true?

    • Options
    • A. {3, 4} ? A
    • B. {3, 4} ? A
    • C. 1 ? A
    • D. {1, 2, 5} ? A
    • Discuss
    • 5. 
      Two vessels A and B contains milk and water mixed in the ratio 5 : 3 and 2 : 3. When these mixtures are mixed to form a new mixture containing half milk and half water, they must be taken in the ratio ?

    • Options
    • A. 2 : 5
    • B. 3 : 5
    • C. 4 : 5
    • D. 7 : 3
    • Discuss
    • 6. 
      1, 2, 4, 8, 16, 32, 64, (...), 256?

    • Options
    • A. 148
    • B. 128
    • C. 154
    • D. 164
    • Discuss
    • 7. 
      A tree is 12 m tall and casts an an 8 m long shadow. At the same time, a flag pole caste a 100 m long shadow. How long is the flag pole?

    • Options
    • A. 150 m
    • B. 200 m
    • C. 125 m
    • D. 115 m
    • Discuss
    • 8. 
      8% of 96 =? of 1/25

    • Options
    • A. 19.2
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    • C. 1.92
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    • Discuss
    • 9. A certain amount earns simple interest of Rs. 1750 after 7 years. Had the interest been 2% more, how much more interest would it have earned?

    • Options
    • A. Rs. 35
    • B. Rs. 245
    • C. Rs. 350
    • D. Cannot be determined
    • E. None of these
    • Discuss
    • 10. 
      If the hands of a clock coincide in every 65 minutes (true time), in 24 hours the clock will gain:

    • Options
    • A. 10 10 minutes. 143
    • B. 9 12 minutes. 143
    • C. 11 12 minutes. 143
    • D. 12 10 minutes. 143
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