Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Nov 1912:30 PM EST
-01:30 PM EST
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more
Nov 2007:30 AM PST
-08:30 AM PST
Learn what truly sets the UC Riverside MBA apart and how it helps in your professional growth
Nov 2001:30 PM EST
-02:30 PM IST
Learn how Kamakshi achieved a GMAT 675 with an impressive 96th %ile in Data Insights. Discover the unique methods and exam strategies that helped her excel in DI along with other sections for a balanced and high score.
Nov 2211:00 AM IST
-01:00 PM IST
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment- Nov 23
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Nov 2407:00 PM PST
-08:00 PM PST
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
Nov 2510:00 AM EST
-11:00 AM EST
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
10 Jul 2025, 08:00
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
76% (01:21) correct
24%
(01:10)
wrong
based on 251
sessions
History
Date
Time
Result
Not Attempted Yet
Over a 4-hour shift, Mark loaded a total of 80 boxes into a truck. What was the average (arithmetic mean) weight of the boxes he loaded during the shift?
(1) During the first 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 20 kilograms.
(2) During the last 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 30 kilograms.
(1) During the first 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 20 kilograms.
(2) During the last 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 30 kilograms.
|
10 Jul 2025, 08:30
Kudos
Bookmarks
Over a 4-hour shift, Mark loaded a total of 80 boxes into a truck. What was the average (arithmetic mean) weight of the boxes he loaded during the shift?
This is not a hard problem per se, but if read carelessly, one can easily make a blunder.
(1) During the first 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 20 kilograms.
This statement is clearly insufficient because it provides no information about the second half of the shift.
(2) During the last 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 30 kilograms.
Similarly, this statement is insufficient since it provides no information about the first half of the shift.
(1) + (2) When taken together, note that we cannot assume Mark loaded half the boxes in each half of the shift. Since we don’t know how many boxes were loaded during each half, we cannot compute the overall average.
For example, if 1 box weighing 20 kg was loaded in the first half and 79 boxes averaging 30 kg in the second half, the overall average would be (1 * 20 + 79 * 30)/80 = 29.something. But if 79 boxes averaging 20 kg were loaded in the first half and 1 box weighing 30 kg in the second half, the overall average would be (79 * 20 + 1 * 30)/80 = 20.something kg. Not sufficient.
Answer: E.
GMAT Club Official Explanation:
Over a 4-hour shift, Mark loaded a total of 80 boxes into a truck. What was the average (arithmetic mean) weight of the boxes he loaded during the shift?
This is not a hard problem per se, but if read carelessly, one can easily make a blunder.
(1) During the first 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 20 kilograms.
This statement is clearly insufficient because it provides no information about the second half of the shift.
(2) During the last 2 hours of the shift, the average (arithmetic mean) weight of the boxes Mark loaded was 30 kilograms.
Similarly, this statement is insufficient since it provides no information about the first half of the shift.
(1) + (2) When taken together, note that we cannot assume Mark loaded half the boxes in each half of the shift. Since we don’t know how many boxes were loaded during each half, we cannot compute the overall average.
For example, if 1 box weighing 20 kg was loaded in the first half and 79 boxes averaging 30 kg in the second half, the overall average would be (1 * 20 + 79 * 30)/80 = 29.something. But if 79 boxes averaging 20 kg were loaded in the first half and 1 box weighing 30 kg in the second half, the overall average would be (79 * 20 + 1 * 30)/80 = 20.something kg. Not sufficient.
Answer: E.
General Discussion
Emkicheru
Joined: 12 Sep 2023
Last visit: 12 Sep 2025
Posts: 119
Own Kudos:
Given Kudos: 11
Location: Kenya
Schools: Anderson (UCLA) Sloan (MIT) Columbia '27
GMAT 1: 780 Q50 V48
GRE 1: Q167 V164
GPA: 3.7
Schools: Anderson (UCLA) Sloan (MIT) Columbia '27
GMAT 1: 780 Q50 V48
GRE 1: Q167 V164
Posts: 119
Kudos:
22
10 Jul 2025, 08:28
Kudos
Bookmarks
Bunuel
The average AM in the four hours is (20+30)=50/2=25
