## Don’t lose your progress!

We cover every section of the GMAT with in-depth lessons, 5000+ practice questions and realistic practice tests.

## Up to 90+ points GMAT score improvement guarantee

### The best guarantee you’ll find

Our Premium and Ultimate plans guarantee up to 90+ points score increase or your money back.

## Master each section of the test

### Comprehensive GMAT prep

We cover every section of the GMAT with in-depth lessons, 5000+ practice questions and realistic practice tests.

## Schedule-free studying

### Learn on the go

Study whenever and wherever you want with our iOS and Android mobile apps.

## The most effective way to study

### Personalized GMAT prep, just for you!

Adaptive learning technology focuses on your academic weaknesses.

# Data Sufficiency: The Question Stem - What is the Issue?

If \$\$M\$\$ is a sequence of consecutive integers which contains more than 11 terms, what is the average of \$\$M\$\$? >(1) In \$\$M\$\$, the number of terms that are less than 10 is equal to the number of terms greater than 21. >(2) There are 20 terms in \$\$M\$\$.
Correct. [[snippet]] Stat. (1): Since \$\$M\$\$ is a set of consecutive integers, it includes all the integers between its smallest and largest terms, including the integers between 10 and 21. Focus on 15.5, the midpoint between 10 and 21. Since the number of terms greater than 21 is equal to the number of terms smaller than 10, the median of \$\$M\$\$ (and thus the average) must be 15.5. If you're not sure, __Plug In__ several sets of integers with equal numbers on either side of the 10–21 interval—the average will always equal 15.5. **Stat.(1) → S → AD**. Stat. (2): The fact that there are 20 terms in \$\$M\$\$ is not __sufficient__ alone to determine the average, as the terms themselves may vary. Set \$\$M\$\$ could include the set of integers between 1 and 20, inclusive, or the set of integers between 1,001 and 1,020, inclusive. No single value can be determined for the average of \$\$M\$\$, so **Stat.(2) → IS → A**.
Incorrect. [[snippet]] Stat. (1): Since \$\$M\$\$ is a set of consecutive integers, it includes all the integers between its smallest and largest terms, including the integers between 10 and 21. Focus on 15.5, the midpoint between 10 and 21. Since the number of terms greater than 21 is equal to the number of terms smaller than 10, the median of \$\$M\$\$ (and thus the average) must be 15.5. If you're not sure, __Plug In__ several sets of integers with equal numbers on either side of the 10–21 interval—the average will always equal 15.5. **Stat.(1) → S → AD**.
Incorrect. [[snippet]] Stat. (2): The fact that there are 20 terms in \$\$M\$\$ is not __sufficient__ alone to determine the average, as the terms themselves may vary. Set \$\$M\$\$ could include the set of integers between 1 and 20, inclusive, or the set of integers between 1,001 and 1,020, inclusive. No single value can be determined for the average of \$\$M\$\$, so **Stat.(2) → IS → ACE**.
Statement (1) ALONE is sufficient, but Statement (2) alone is not sufficient to answer the question asked.
Statement (2) ALONE is sufficient, but Statement (1) alone is not sufficient to answer the question asked.
BOTH Statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.
EACH statement ALONE is sufficient to answer the question asked.
Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the problem are needed.