e-GMAT Logo
NEUR
N

Sofia will attend a sequence of daily training sessions for her job. On the last day of her training sessions...

GMAT Data Sufficiency : (DS) Questions

Source: Mock
Data Sufficiency
DS-Basics
MEDIUM
...
...
Notes
Post a Query

Sofia will attend a sequence of daily training sessions for her job. On the last day of her training sessions she will attend either 1 session or 2 sessions. On each of the other days of her training sessions she will attend exactly 2 sessions. At the end of her third day of attending training sessions, how many sessions will Sofia have left to attend?

  1. The sequence of training sessions Sofia will attend will last 6 days.
  2. There are a total of 11 training sessions in the sequence of training sessions Sofia will attend.
A
Statement (1) ALONE is sufficient but statement (2) ALONE is not sufficient.
B
Statement (2) ALONE is sufficient but statement (1) ALONE is not sufficient.
C
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D
EACH statement ALONE is sufficient.
E
Statements (1) and (2) TOGETHER are not sufficient.
Solution

Understanding the Question

Let's break down what's happening in Sofia's training program:

  • She attends 2 sessions every day EXCEPT the last day
  • On the last day, she attends either 1 OR 2 sessions
  • We need to find: How many sessions remain after her third day?

What We Need to Determine

To answer this question, we need to know:

  1. The total number of sessions in the program
  2. How many sessions she completes by the end of day 3

Since Sofia always attends 2 sessions per day (except possibly the last day), by the end of day 3 she will have completed exactly 6 sessions (\(2 \text{ sessions/day} \times 3 \text{ days} = 6 \text{ sessions}\)).

Therefore, we really need to determine the total number of sessions in the program.

Analyzing Statement 1

Statement 1: The training lasts 6 days.

Let's think through what this means. If the training is 6 days long:

  • Days 1-5: 2 sessions each = 10 sessions
  • Day 6 (last day): Either 1 or 2 sessions
  • Total: Either 11 or 12 sessions

By the end of day 3, Sofia has completed 6 sessions.

This gives us two possible scenarios:

  • If total = 11 sessions → \(11 - 6 = 5\)5 sessions remaining
  • If total = 12 sessions → \(12 - 6 = 6\)6 sessions remaining

Since we get two different answers (5 or 6), Statement 1 alone is NOT sufficient.

This eliminates choices A and D.

Analyzing Statement 2

Now let's forget Statement 1 completely and analyze Statement 2 independently.

Statement 2: There are exactly 11 training sessions total.

This is a powerful constraint. Let's work backwards to see what this tells us about the program structure.

If the last day has 1 session:

  • Other days must have: \(11 - 1 = 10\) sessions
  • At 2 sessions per day: \(10 \div 2 = 5\) days
  • Total program length: \(5 + 1 = 6\) days

If the last day has 2 sessions:

  • Other days must have: \(11 - 2 = 9\) sessions
  • At 2 sessions per day: \(9 \div 2 = 4.5\) days
  • But we can't have half a day! ✗

The key insight: 11 total sessions forces exactly one possible structure - the program must be 6 days long with the last day having only 1 session.

By the end of day 3, Sofia completes 6 sessions.
Sessions remaining: \(11 - 6 = 5\) sessions

[STOP - Sufficient!] We get exactly one answer.

Statement 2 alone is sufficient.

This eliminates choices C and E.

The Answer: B

Statement 2 alone provides enough information to determine that exactly 5 sessions remain after Sofia's third day, while Statement 1 alone leaves us with two possible answers.

Answer Choice B: "Statement 2 alone is sufficient, but Statement 1 alone is not sufficient."

Answer Choices Explained
A
Statement (1) ALONE is sufficient but statement (2) ALONE is not sufficient.
B
Statement (2) ALONE is sufficient but statement (1) ALONE is not sufficient.
C
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D
EACH statement ALONE is sufficient.
E
Statements (1) and (2) TOGETHER are not sufficient.
Rate this Solution
Tell us what you think about this solution
...
...
Forum Discussions
Start a new discussion
Post
Load More
Similar Questions
Finding similar questions...
Previous Attempts
Loading attempts...
Similar Questions
Finding similar questions...
Parallel Question Generator
Create AI-generated questions with similar patterns to master this question type.
Sofia will attend a sequence of daily training sessions for : Data Sufficiency (DS)