If (a + b) / c = 6/5, and (b + c) / a = 9/2, then what is the value of (a + c) / b?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 7/4
⇒ (a + b)/c = 6/5
5a + 5b = 6c --------- eq1
⇒ (b + c)/a = 9/2
2b + 2c = 9a ---------- eq2
⇒ 9a - 2b = 2c (multiply by 3)
27a - 6b = 6c --------- eq3
from eq1 and eq3
⇒ 27a - 6b = 5a + 5b
b = 2a
⇒ 4a + 2c = 9a
c = (5/2)a
⇒ (a + c)/b = [a + (5/2)a] / 2a
= (7a/4a)
= 7/4