Critical Reasoning

According to a recent magazine article, of those office employees who typically work 8 hours at the office each day but sometimes say that they will work at home on a particular day, 25 percent actually work less than one hour. At the same time, over 90 percent of those same office employees believe they are more productive working at home than working in their office.

The statements above, if true, best support which of the following conclusions about the office employees discussed in the article?

a) On average, the office employees working at home for a day work fewer hours than office employees working at the office.

b) 10 percent of the office employees are less productive working from home than working in their office.

c) At least 15 percent of the office employees do not define productivity exclusively in terms of the number of hours worked.

d) At least 25 percent of the office employees can complete the same amount of work in one hour at home as in 8 hours at the office.

e) Some of the office employees make statements regarding their productivity that are not in fact true.

This question is from MGMAT and many people consider it a difficult one.

The OA is C.

The explanation is thus:

90% of those employees who are working at home say that they are more productive. Yet, 25% of those working at home work less than 1 hour.

Think of this as a Venn Diagram! One circle is "Think they are more productive" and another circle is "work less than 1 hour" You can see that 90 + 25 equals 115 so at least 15% need to be in the "both" category.

Of course, it is possible that there are some who "neither work less than an hour nor feel more productive" in which case the overlap between the circles could be as high as 25%.

So somewhere between 15 and 25% of workers - who usually work for 8 hours per day in the office - work less than an hour at home and somehow think they are more productive. They must have a nice definition of productive! That is where choice C comes in.

Does that help?

David

Thinking to use a Venn Diagram and then ultimately deriving 15% from adding 90 and 25 would have never crossed my mind. I didn't Quant folding into Verbal! I chose D because it seemed the most logical. The 15% answer in C left me wondering how that number was even derived so I just assumed it was wrong. But still, how would you get 15% from 115%?

Jesse

According to a recent magazine article, of those office employees who typically work 8 hours at the office each day but sometimes say that they will work at home on a particular day, 25 percent actually work less than one hour. At the same time, over 90 percent of those same office employees believe they are more productive working at home than working in their office.

The statements above, if true, best support which of the following conclusions about the office employees discussed in the article?

On average, the office employees working at home for a day work fewer hours than office employees working at the office.

10 percent of the office employees are less productive working from home than working in their office.

At least 15 percent of the office employees do not define productivity exclusively in terms of the number of hours worked.

At least 25 percent of the office employees can complete the same amount of work in one hour at home as in 8 hours at the office.

Some of the office employees make statements regarding their productivity that are not in fact true.

Given 100 employees who sometimes work at home:
90 believe that they are MORE PRODUCTIVE AT HOME.
25 work LESS THAN 1 HOUR.
Since 90+25 = 115, and the total = 100, AT LEAST 15 employees are members of both groups, believing that they are MORE PRODUCTIVE at home even though they work LESS THAN 1 HOUR.
For these 15 employees, productivity does not depend on the number of hours worked.

The facts above support answer choice C: At least 15 percent of the office employees do not define productivity exclusively in terms of the number of hours worked.

The correct answer is C.

So are you just assuming there's 100 workers since the numbers that are provided are percents?

Rastis wrote:So are you just assuming there's 100 workers since the numbers that are provided are percents?

The number of workers could be any value.
I plugged in 100 workers in order to make the relationships easier to see.

Rastis wrote:
So are you just assuming there's 100 workers since the numbers that are provided are percents?

Actually the numbers in the problem are in percentages. And as you know the total is always 100%!

So if we get 115% we know that something has been counted too many times.

And remember that we do not have exactly 15% that are in the both category, but anywhere from 15 to 25% and that is why choice C works so well. It says "At least 15%"