inequality

This topic has expert replies
Source: — Data Sufficiency |

Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

by clock60 » Sat Jul 02, 2011 2:42 am
hi hope that the answer is E here
(1) x=0, y=2, xy=0<9 no
x=1,y=10, xy=10>9 yes, so insuff
(2)y=0, x=2, xy=0<9 no
x=9,y=2, xy=18>9 yes. again insuff
from both we can see that
2<=x<=4, and 2<=y<=4
x=2,y=2, xy=4<9 no
x=4,y=4, xy=16>9 yes
so E