Question
If a : b = 20:5 then find out the value of (13a-9b): (11a-7b)?
A. 43/42
B. 40/33
C. 43/37
D. 44/37
Answer: C – 43/37
Solution:
a : b = 20 : 5
a/b = 20/5 = 4
=> a = 4b
=> (13a – 9b) : (11a – 7b)
=> (13 (4b) – 9 (b)) / (11 (4b) – 7 (b))
=> 52b – 9b / 44b – 7b
=> 43b / 37b
=> 43/37
(13a – 9b) : (11a – 7b) Answer is 43/37.