RiyaR wrote:Of the following, which if closest to ?
(0.15*495)/9.97
(A) 7.5
(B) 15
(C) 75
(D) 150
(E) 750

As Mitch mentioned, the answer choices are spread out, so we can use some estimation. In fact, I'd say the answer choices a VERY SPREAD OUT, which means we can be SUPER lenient with our estimation.
So, another way to tackle the question is to recognize that 0.15 is close to 1/7, 495 is close to 490, and 9.97 s close to 10.
So, we get: (1/7)(490)/10 = 70/10 = 7
Answer choice A is the only answer choice close to 7, so it must be the correct answer.

This strategy and others are covered in our free video, "General GMAT Math Strategies": https://www.gmatprepnow.com/module/gener ... es?id=1111

Cheers,
Brent

Hi RiyaR,

Each of the given explanations essentially explains the same thing, so I won't rehash any of that here.

I can tell you that the GMAT will ask you to perform at least 1 approximation during the Quant section (it's a built in "skill test" that is a part of every Test Taker's exam). Beyond that, you should be ready to use the answer choices to your advantage. When the answers are properly "spaced out", as they are in this prompt, you have an opportunity to save time by NOT performing the exact calculation that is given. Be on the lookout for these opportunities.

The exception to this rule is when the answer choices are "decimal shifted."

For example:
.02
.2
2
20
200

These types of questions are almost always based on PEMDAS rules, so you MUST perform the proper calculations, otherwise you'll be "off" by some factor of 10.

GMAT assassins aren't born, they're made,
Rich