If (a + b) : c = 6 : 5, (b + c) : a = 9 : 2, then (a + c) : b = ?

In these type of questions always note that the total amount/ratio must be same in all conditions.

⇒ (a + b) : c = 7 : 6  = 13 (total)

⇒ (b + c) : a = 9 : 4  = 13 (total)

total equal is already equal,

Therefore,

a = 4 , c = 6  &  b = 13 - (4 +6) = 3

Here,

⇒ (a + c) : b = 10 : 3