Problem Solving

Hey guys, here is another one !

0 < r < 1 < s < 2

Which of the following must be < 1 ?

I) r/s
II) rs
III)s-r


A) I only
B) II only
C) III only
D) I & II
E) I & III



r = 1/2 s = 3/2

I) r/s = (1/2)/(3/2) = (1/2) * (2/3) = 1/3 --> true
II) rs = (1/2)*(3/2) = 3/4 --> true
III) s-r = 3/2 - 1/2 = 2 --> false

Other numerical test:
r = 1/100 s = 199 / 100

I)r/s = (1/100) / (199/100) = 1/199 ---> true
II) rs = (1/100) * (199/100) = 199/1000 --> true
III) s-r = (199/100)-(1/100) = 198/100 --> false

IMO : D

OA : A