Data Sufficiency

BTGModeratorVI wrote: ↑

Fri Jul 03, 2020 7:01 am

How many of the 42 people in a group are employed students?

(1) 29 of the 42 people are employed.
(2) 24 of the 42 people are students.

Answer: E
Source: GMAT prep

Let's take each statement one by one.

(1) 29 of the 42 people are employed.

Certainly insufficient as we do not know how many among the 29 are students.

(2) 24 of the 42 people are students.

Certainly insufficient as we do not know how many among the 24 are employed.

(1) and (2) together

The maximum no. of employed students can be 24, while the minimum no. of employed students can be 11. No unique value. Insufficient.

Correct answer: E

Hope this helps!

-Jay
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BTGModeratorVI wrote: ↑

Fri Jul 03, 2020 7:01 am

How many of the 42 people in a group are employed students?

(1) 29 of the 42 people are employed.
(2) 24 of the 42 people are students.

Answer: E
Source: GMAT prep

Here's a step-by-step approach using the Double Matrix method.

Here, the criteria are:
- employment status (employed or unemployed)
- schooling (student or non-student)

There are 42 people altogether, so our first diagram looks like this:


Notice that I placed a star in the top-left box. The target question asks us to determine the number of people in this box.

Statement 1: 29 out of 42 are employed.
We get:

Since we cannot find the number of people in the top-left box, statement 1 is NOT SUFFICIENT

Statement : 24 out of 42 are students.
We get:

Since we cannot find the number of people in the top-left box, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined:
We get:

Since we still cannot find the number of people in the top-left box, the combined statements are NOT SUFFICIENT

Answer: E

This question type is VERY COMMON on the GMAT, so be sure to master the technique.

To learn more about the Double Matrix Method, watch this video: https://www.gmatprepnow.com/module/gmat- ... ems?id=919

Once you’re familiar with this technique, you can attempt these additional practice questions:

Easy Problem Solving questions
- https://www.beatthegmat.com/finance-majo ... 67425.html

Medium Problem Solving questions
- https://www.gmatprepnow.com/module/gmat- ... /video/920
- https://www.beatthegmat.com/posted-speed ... 72374.html
- https://www.beatthegmat.com/motel-t271938.html
- https://www.beatthegmat.com/of-the-appli ... 70255.html
- https://www.beatthegmat.com/opening-nigh ... 64869.html
- https://www.beatthegmat.com/at-least-100 ... 74669.html
- https://www.beatthegmat.com/prblem-solving-t279424.html

Difficult Problem Solving questions
- https://www.gmatprepnow.com/module/gmat- ... /video/946
- https://www.beatthegmat.com/ratio-problem-t268339.html
- https://www.beatthegmat.com/overlapping- ... 65223.html
- https://www.beatthegmat.com/fractions-t264254.html
- https://www.beatthegmat.com/overlapping- ... 64092.html
- https://www.beatthegmat.com/mba/2011/05/ ... question-2

Easy Data Sufficiency questions
- https://www.gmatprepnow.com/module/gmat- ... /video/943
- https://www.beatthegmat.com/for-what-per ... 70596.html
- https://www.beatthegmat.com/ds-quest-t187706.html

Medium Data Sufficiency questions
- https://www.beatthegmat.com/sets-matrix-ds-t271914.html
- https://www.beatthegmat.com/each-of-peop ... 71375.html
- https://www.beatthegmat.com/a-manufacturer-t270331.html
- https://www.beatthegmat.com/in-costume-f ... 69355.html
- https://www.beatthegmat.com/mba/2011/05/ ... question-1

Difficult Data Sufficiency questions
- https://youtu.be/dsCeqF9Kbk8
- https://www.beatthegmat.com/double-set-m ... 71423.html
- https://youtu.be/dOZ9KM1m5Hs
- https://www.beatthegmat.com/sets-t269449.html
- https://www.beatthegmat.com/mba/2011/05/ ... question-3

Cheers,
Brent