DS question

[gmatmillenium]

m and r are two numbers in a number line, what is the value of r?

1. distance between r and 0 is 3 times the distance between m and 0
2. 12 is halfway between m and r

[outreach]

m and r are two numbers in a number line, what is the value of r?

1. distance between r and 0 is 3 times the distance between m and 0
2. 12 is halfway between m and r

we do not know whether m and r is positive or negative

option 1
|r-0|=3*|m-0|
squaring we get
r^2=9m^2
so r can be +/- 3m
hence not sufficient

option 2
(r+m)/2=12
r+m=24
hence not sufficient

combining
if r is -3m then we m-3m=24=>m = -12, r = 36
if r is +3m then we m+3m=24=>m = 6, r = 18

hence not sufficient

E