GMAT Prep expressionsss

moneyman · Posted: Sat May 10, 2008 7:27 am Post subject: GMAT Prep expressionsss

Easy question but missed out on something

Is x+y<1 ?

(1)x<8/9

(2)y<1/8

Ans E

I chose C

My approach : Each statement cannot be sufficient with differing values for x and y . (1) says x<8/9 or x< 0.88 and (2) says y<1/8 or y<0.12 so lets say x is 0.87 and y is 0.11 then for all values x+y will be less than 1.

Where did I go wrong ?

VP_Jim · Posted: Sat May 10, 2008 6:36 pm Post subject:

Hi moneyman,

The way you approached the problem is great, you just needed to take it a step further. Try plugging in the max numbers for X and Y (for example, 8/9 + 1/8 ), keeping in mind that you need to keep these numbers 0.00000001 (or a really small number, you get the point) less than what you actually plugged in. If you add 8/9 and 1/8, you'll find that it's actually greater than 1 (73/72). Remember that this number is really 72.99999999/72 (and note that it didn't make a difference that we estimated). Thus, the answer is E!

Hope this helps!