If a:b=2:3, b:c=6:5 and a+b+c=30, then 2a+3b+4c is

(a) 30
(b) 92
(c) 100
(d) 90

Anurag Mishra Professor Asked on 29th February 2016 in Maths.
Add Comment
  • 1 Answer(s)
    Best answer

    Answer: (b) 92 

    Solution:-
    a: b = 2: 3,  b: c = 6: 5
    Then, a: b: c = 2 x 6: 3 x 6: 3 x 5
     = 12: 18: 15
     a: b: c = 4: 6: 5

    Let a, b and c be 4 X, 6 X & 5 X
    a + b + c = 30            (Given)
    Then, 4 X + 6 X + 5 X = 30
     15 X = 30
    X = 30/15
    X = 2

    Then, the value of a = 4 x 2 = 8, b = 6 x 2 = 12 & c = 5 X = 5 x 2 = 10. 

    So, the value of  2 a + 3 b + 4 c = 8 x 2 + 12 x 3 + 4 x 10
     = 16 + 36 + 40
     = 92. 

    Hence, the correct answer is option (b) 92. 

    Anurag Mishra Professor Answered on 1st March 2016.
    Add Comment
  • Your Answer

    By posting your answer, you agree to the privacy policy and terms of service.