Is ab 2?

Question

Is ab > 2?

(1) a = 2
(2) 0 < a/b < 1

abhimahna · Answer

Answer should be C. Statement 1 : We don't know the value of b. hence, Insufficient. Statement 2 : 0 < a/b < 1 => a and b must be of same sign AND a must be less than b. Hence, if we take the closest values of a and b say 1 and 2, we will get the product 2 which is not > 2. And if we take a=1, b=5 we will get a*b > 2 Hence, insufficient. Combining, we know a=2, b can be anything greater than 2. Hence, product will always be >2. Hence Sufficient.

laddaboy · Answer

1) a= 2

2*b > 2

For b = 1 , 0 condition fails and For b = 2 condition holds. Hence 1 is Insuff

2) 0<a/b<1

a=9 b =10 => ab = 90 > 2
a=0.1 b = 1 => ab = 0.1 < 2 Hence 2 is Insuff

Combining 1 and 2

0<2/b<1 i.e 0<2<b or b>2

a= 2 and b >2 => ab is always greater than 2. Sufficient

Hence C

_________________

Consistency is the Key

Signature Read More

Is ab > 2?

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia