[-1.6] = -2 (Greatest integer less than equal to x: Here -2,-3,-4... are less than -1.6 but -2 is greatest among them)
[3.4] = 3
[2.7] = 2

IMO [spoiler] -2+3+2 = 3 A[/spoiler]

Hey guys,

Great explanation from shovan that I just want to call more attention to.

This isn't a difficult problem...the math is almost too easy...it nets out to 3 + 2 - 2. However, quite a few people will miss this problem because they haven't considered exactly what shovan mentions: -2 is less than -1.6, but -1 is actually greater than -1.6. The natural knee-jerk reaction when you see a negative number and want to make it smaller is to think in terms of positive numbers and to go from -1.6 ---> -1. But that negative symbol puts you on a number line, on which the smaller the number the further left you go:

<--------------------------------------------------------------------------------->
-5 ... -4 ... -3 ... -2 ... -1.6 ... -1 ... 0 ... 1 ... 2 ... 3 ... 4 ... 5.....


Number lines tend to seem too basic to adults...we learned those in elementary school! But thinking in these simple terms helps you to understand the ways that the GMAT adds "subtle difficulty" to its questions.

A challenge to everyone here - when you go through these problems and concepts try to ask yourself where the GMAT is adding or could add more difficulty. The fact that as a negative number decreases its absolute value increases is a great example of that - when you're thinking quickly your mind can work against you on a problem like this! Pause in your studies to really focus on some of those subtle-difficulty concepts - even when you get problems right - so that you develop that internal conscience that helps you to slow down on the test when you're navigating a situation that doesn't look hard, but might actually be.