BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Can't solve this!

Expert replies
by ketaki6 » Thu Jul 28, 2011 7:41 pm
On Jane's credit card account, the average daily balance for a 30-day billing cycle is the average (arithmetic mean) of the daily balances at the end of each of the 30 days. At the beginning of a certain 30-day cycle, Jane's credit card account had a balance of $600. Jane made a payment of $300 on the account during the billing cycle. If no other amounts were added to or subtracted from the account during the billing cycle, what was the average daily balance on Jane's account for the billing cycle?

1. Jane's payment was credited on the 21st day of the billing cycle
2. The average daily balance through the 25th day of the billing cycle was $540.

a. Statement 1 alone
b. Statement 2 alone
c. Both together
d. Each alone sufficient
e. 1 and 2 not sufficient together


I understand 1. But I just don't get how 2. works out. Help please.
Join the discussion
Source: — Data Sufficiency |

by sanju09 » Sat Jul 30, 2011 3:26 am
ketaki6 wrote:On Jane's credit card account, the average daily balance for a 30-day billing cycle is the average (arithmetic mean) of the daily balances at the end of each of the 30 days. At the beginning of a certain 30-day cycle, Jane's credit card account had a balance of $600. Jane made a payment of $300 on the account during the billing cycle. If no other amounts were added to or subtracted from the account during the billing cycle, what was the average daily balance on Jane's account for the billing cycle?

1. Jane's payment was credited on the 21st day of the billing cycle
2. The average daily balance through the 25th day of the billing cycle was $540.

a. Statement 1 alone
b. Statement 2 alone
c. Both together
d. Each alone sufficient
e. 1 and 2 not sufficient together


I understand 1. But I just don't get how 2. works out. Help please.

(1) If Jane's payment was credited on the 21st day of the billing cycle, then the average daily balance for the 30-day billing cycle can be given by

$(20 × 600 + 10 × 300)/30. Sufficient

(2) Let Jane's payment was credited on the nth day of the billing cycle, then the average daily balance through the 25th day of the billing cycle can be given by

$[(n - 1) × 600 + (25 - n + 1) × 300]/25 = $540 (given);

n can be uniquely found out and hence the average daily balance for a 30-day billing cycle. [spoiler]Sufficient

D
[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Join the discussion

by GMATGuruNY » Sat Jul 30, 2011 4:12 am
ketaki6 wrote:On Jane's credit card account, the average daily balance for a 30-day billing cycle is the average (arithmetic mean) of the daily balances at the end of each of the 30 days. At the beginning of a certain 30-day cycle, Jane's credit card account had a balance of $600. Jane made a payment of $300 on the account during the billing cycle. If no other amounts were added to or subtracted from the account during the billing cycle, what was the average daily balance on Jane's account for the billing cycle?

1. Jane's payment was credited on the 21st day of the billing cycle
2. The average daily balance through the 25th day of the billing cycle was $540.

a. Statement 1 alone
b. Statement 2 alone
c. Both together
d. Each alone sufficient
e. 1 and 2 not sufficient together


I understand 1. But I just don't get how 2. works out. Help please.
To determine the average of the daily balances for the whole month, we need to determine when Jane made the $300 payment.

Statement 1: Jane's payment was credited on the 21st day of the billing cycle.
Sufficient.

Statement 2: The average daily balance through the 25th day of the billing cycle was $540.
If statement 2 also is sufficient, it must confirm the same information given in statement 1: that the payment was made on the 21st day.
Total for 20 days with an average daily balance of 600 = 20*600 = 12000.
After the payment is made, total for 5 days with an average daily balance of 300 = 5*300 = 1500.
Average for the first 25 days = (12000+1500)/25 = 13500/25 = 540.
Thus, the payment was made on the 21st day.
If the payment had been made on any other day, the total for the first 25 days would change, yielding an average higher or lower than 540.
Sufficient.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Join the discussion

by ketaki6 » Sat Jul 30, 2011 9:13 am
Thanks a lot. The mistake I made was I assumed payment to the account means payment towards his account. So instead of doing 600 - 300, I did 600 + 300.
Join the discussion