inequality

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Thu Jun 09, 2011 1:50 pm

inequality

by cricfan31 » Tue Jul 19, 2011 12:44 am
can someone suggest a better way other than trying out numbers, to resolve the problem
Attachments
Inequality.png

Senior | Next Rank: 100 Posts
Posts: 52
Joined: Wed May 18, 2011 8:48 pm
Thanked: 4 times

by newgmattest » Tue Jul 19, 2011 12:52 am
The first statement reduces to m > 3z, which can definitely be satisfied by two positive numbers, and can definitely be satisfied by two negative numbers. Therefore, this statement is insufficient.

The second statement reduces to 4z > m, which can definitely be satisfied by two positive numbers, and can definitely be satisfied by two negative numbers. Therefore, this statement is insufficient.

Then consider both together: 3z<M<4z. If 3z<4z, then z must be positive since this would not hold for negative value of z. If z is positive, then 3z is also positive and if M is greater then 3z, then M is also positive. If M and z are positive, then m+z >0 must always be true and the answer is C.