A lot of GMAT takers ask about “Guesstimate”. Let’s break it down in this blog.
First off, what is a guesstimate? As most of you know, when you’re estimating what an answer will be based on a mixture of guesswork and calculation, you’re guesstimating.
So when should you be doing it when you’re tackling the GMAT?
The answer is actually pretty simple. You should be guesstimating if
a) you are running out of time, OR
b) If you are unsure of the answer, OR
c) If you find that calculation could be too tedious to get to the answer
Now, let’s tackle the next most obvious question: How should you Guesstimate?
Hence, you may choose the option nearest to the guestimated value.
Now let’s look at guesstimating with an example.
Yesterday, 4,840 members of a club were divided into two teams – Team A and Team B – to help in fundraising for an upcoming donation camp. Today, all the team members changed their teams and none of them were in the same team as yesterday. The number of members that are in Team A today is 20 percent higher than the number of members in Team B today. How many of the club members were in Team B yesterday?
Let’s try to interpret the question.
The question asks for “the number of club members that were in Team B yesterday“, which is nothing but the number of club members in Team A today.
And, we know that the number of club members that are in Team A today is slightly more than the number of club members that are in Team B today, that is 20% higher.
So, an easier way is to divide the total number in two equal halves i.e. 4840 / 2 = 2,420 and to redistribute these two equal halves 2420 and 2420 by removing approximately 10% from one and adding approximately 10% to other. (You don’t really need to calculate the latter part, this just states that the number of members in Team A yesterday was less than 2420 and the number of members in Team B yesterday was more than 2420).
Hence, Choices (A), (B) and (C) can be eliminated.
Now, lets look at choices D and E.
Choice (E) is approximately 40% more than 2420 (you don’t need to calculate it). Hence, E is also eliminated.
So, the correct answer is (D) 2640!
Now wasn’t that simple?
Stay tuned to this blog for more GMAT Study Tips.