What is the average of 1/2, 2/5 and 3/10?

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What is the average of 1/2, 2/5 and 3/10?

by VJesus12 » Thu Dec 28, 2017 4:53 am
What is the average of 1/2, 2/5 and 3/10?

A. 1/5
B. 3/10
C. 2/5
D. 1/2
E. 6/5

The OA is the option C.

Experts, is there a fast way to solve this PS question? Thanks in advanced.

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by EconomistGMATTutor » Thu Dec 28, 2017 8:57 am
Hello Vjesus12.

Let's see your question.

We can rewrite this numbers to get an easy way to find the average. We can rewrite and reorder the numbers as follows: $$\frac{3}{10}\ \ \ ,\ \ \ \ \ \frac{2}{5}=\frac{4}{10}\ \ \ ,\ \ \ \ \frac{1}{2}=\frac{5}{10}\ .$$ Therefore, the average is given by $$\frac{\frac{3}{10}+\frac{4}{10}+\frac{5}{10}}{3}=\ \frac{\frac{12}{10}}{3}=\frac{12}{30}=\frac{2}{5}.$$ So, the correct answer is the option [spoiler]C=2/5[/spoiler].

I hope this explanation may help you.

I'm available if you'd like a follow-up.

Regards.
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by GMATWisdom » Thu Dec 28, 2017 9:25 am
VJesus12 wrote:What is the average of 1/2, 2/5 and 3/10?

A. 1/5
B. 3/10
C. 2/5
D. 1/2
E. 6/5

The OA is the option C.

Experts, is there a fast way to solve this PS question? Thanks in advanced.
The faster way depends on the given fractions only . For example in this case you clearly see that the fractions are equal to
0.5, 0.4 and 0.3 and their average as is visible = 0.4 = 2/5 Hence option C

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by [email protected] » Thu Dec 28, 2017 9:49 am
Hi VJesus12,

We're asked to find the average of 1/2, 2/5 and 3/10. With many GMAT questions (in both the Quant and Verbal sections), the way that you choose to organize your information will greatly impact how quickly you can answer the specific question that is asked. Here, converting these three fractions to decimals creates a significant 'shortcut' that can help you to quickly answer the question.

1/2 = .5
2/5 = .4
3/10 = .3

Since the three numbers are 'evenly spaced' out, the average will be the MIDDLE number...

Final Answer: C

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by Scott@TargetTestPrep » Tue Sep 17, 2019 8:44 am
VJesus12 wrote:What is the average of 1/2, 2/5 and 3/10?

A. 1/5
B. 3/10
C. 2/5
D. 1/2
E. 6/5

The OA is the option C.

Experts, is there a fast way to solve this PS question? Thanks in advanced.
The average is:

(1/2 + 2/5 + 3/10)/3

Multiplying the entire expression by 10/10, we have:

(5 + 4 + 3)/30 = 12/30 = 2/5

Answer: C

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by Brent@GMATPrepNow » Tue Sep 17, 2019 8:49 am
VJesus12 wrote:What is the average of 1/2, 2/5 and 3/10?

A. 1/5
B. 3/10
C. 2/5
D. 1/2
E. 6/5
If we arrange the 3 numbers in ASCENDING order, we get: 3/10, 2/5, 1/2

So, the AVERAGE must be greater than 3/10 and less than 1/2
This allows us to eliminate A, B, D and E

So, by the process of elimination, the correct answer is C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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