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.