Source: Official Guide for the GMAT 13th Ed. Data Sufficiency; #75 Official Guide for the GMAT 2015 14th Ed. Data Sufficiency; #75

1

Is the positive two-digit integer N less

Is the positive two-digit integer N less 40?

1 Explanation

1

Gravatar Mike McGarry, Magoosh Tutor

Jan 4, 2014 • Comment

Claudia Santosa

Hi Mike, i think you've made a mistake when explaining the sufficiency of statement 2. You combined it with the fact that N = ab where b=6+a (as stated in statement 1). Statement 2 should be sufficient by itself since when b=9 (the max single digit that it can have),N=4(9)-4= 32 which is definitely less than 40, so whatever number less than that will always be <40 so N<40. Thx again for all the explanations and keep up the good work :)

Jun 4, 2015 • Reply

Jonathan , Magoosh Tutor

Hey Claudia! You're absolutely right. We only need to see that 4(9) - 4 = 32 is less than 40 to conclude that all N are less than 40 and statement 2 alone is sufficient. I've made a note so we can fix this. Thanks for pointing this out! :)

Jun 15, 2015 • Reply

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Official Guide for the GMAT 2015 14th Ed.

Official Guide for the GMAT 13th Ed.

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Official Guide for the GMAT 12th Ed.

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Section 6.3 Data Sufficiency

Section 6.3 Data Sufficiency

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