When to Answer BY CONCEPT in GMAT Data Sufficiency Questions

When to answer by CONCEPT in GMAT Data Sufficiency questions…

While it might be tempting to plug in numbers for most DS questions, here’s a case where you don’t really need to. In fact, plugging in might be counter-productive!

It’s helpful to think about what a question is really asking and to work from there.

In a case such as this one, I will separate out the two Statements for you:

1. Note that the right side of S1 will always be positive. Work from this standpoint. See? SUFFICIENT.
2. You can see that 0 and 1 work, but given what’s here, ALL PERFECT SQUARES actually work. That implies of course that some answers will be less than 3 and some will be greater than 3. INSUFFICIENT.

And… we’re done.

Notice how quickly a question like this can go as soon as we understand the concept properly. Watch the video for more details!

GMAT Data Sufficiency is fun!

Is the integer k greater than 3 ?

(1) The sum of -4 and k equals the square of an integer.

(2) k equals the square of an integer.

Any questions? Talk to London GMAT Tutor Rowan Hand right here: