AC= 5, BC = 20

Stmt 1: AB = 25; From the properties of number line, C must be between A and B (does not matter on which side in the line). Sufficient

Stmt 2: A lies to the left of B; C could be between A and B or it could be left to A making AC=5, AB = 15 and BC = 20. Insufficient.

Answer A.

ashforgmat wrote:186) Distance between A and C on the number line is 5. Distance between B and C is 20. Does C lie between A and B?
a. Distance between A and B is 25
b. A lies to the left of B

Stem can be interpreted in chiefly two ways on a number line:

Way 1


C____5____A____________15____________B


Way 2


A____5____C____________20____________________B


(1) Distance between A and B is 25 in the Way 2 above, where C does lie between A and B. Sufficient
(2) It can be seen from the above drawn Way 1 and Way 2 that C may or may not lie between A and B while A lies to the left of B. [spoiler]Insufficient

A[/spoiler]

There are 4 possibilities
when distance between A and C on the number line is 5. Distance between B and C is 20.

I) B------------20------------- C----5-----A

II) B-----------15----------A---5-------C

III) A-----5-----C---------------20----------B

IV) C---5-------A--------15------- ----- B

Does C lie between A and B?
a.) Distance between A and B is 25 , possible in I) and III) where C is between A & B. Suff
b) A lies to the left of B, possible in III) and IV) , where C is not always between A & B . Insuff

kstv wrote:There are 4 possibilities
when distance between A and C on the number line is 5. Distance between B and C is 20.

I) B------------20------------- C----5-----A

II) B-----------15----------A---5-------C

III) A-----5-----C---------------20----------B

IV) C---5-------A--------15------- ----- B

Does C lie between A and B?
a.) Distance between A and B is 25 , possible in I) and III) where C is between A & B. Suff
b) A lies to the left of B, possible in III) and IV) , where C is not always between A & B . Insuff

Just one example is sufficient to accept (1) deny (2) here, that's why the stem can be interpreted in chiefly two ways on a number line.