Bunuel
What is the ratio of x:y:z given xyz not equal to 0?
(1) x + y = 2z
(2) 2x + 3y = z
Given: xyz ≠ 0Question: x:y:z = ?Statement 1: x + y = 2zCase 1: If x = 1 and y = 1 then z = 1 hence x:y:z = 1:1:1
Case 2: If x = 1 and y = 3 then z = 2 hence x:y:z = 1:3:2
Inconsistent answers hence
NOT SUFFICIENT (if you wish to learn the strategy to approach DS questions then you may watch 9 videos on my youtube channel in DS playlist)
Statement 2: 2x + 3y = zCase 1: If x = 1 and y = 1 then z = 5 hence x:y:z = 1:1:5
Case 2: If x = 1 and y = 2 then z = 8 hence x:y:z = 1:2:8
Inconsistent answers hence
NOT SUFFICIENTCOmbining the statementsx + y = 2z
2x + 3y = z
i.e. x+y = 2(2x+3y)
i.e .3x+5y = 0
i.e. x:y = -5:3
If x = -5, y = 3 then z = -1 hence x:y:z =
-5:3:-1If x = 5, y = -3 then z = 1 hence x:y:z =
5:-3:1SUFFICIENTAnswer: Option C
The two ratios -5:3:-1 and 5:-3:1 wouldn't it imply that this two are two different sets of ratio meaning we still don't have an unique value to answer the question ?