Last visit was: 18 Nov 2025, 18:38 It is currently 18 Nov 2025, 18:38
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
   1   2 
User avatar
Vordhosbn
User avatar
Joined: 17 Aug 2021
Last visit: 16 Dec 2024
Posts: 44
Own Kudos:
16
Given Kudos: 303
Posts: 44
Kudos: 16
In May Mrs Lee's earnings were 60 percent of the Lee family' 11 Oct 2024, 11:59
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Number picking is the way to go here. We can assume family of two.

In May: 60, 40 - assume she made $60 and the other person $40 giving us 60%
In June she made 1.2 more giving us 72 and the other person still made $40. 72/112*100 ~ 64%
User avatar
glagad
User avatar
Joined: 03 Jun 2022
Last visit: 18 Nov 2025
Posts: 134
Own Kudos:
20
Given Kudos: 100
Products:
GMAT Club Tests
Posts: 134
Kudos: 20
In May Mrs Lee's earnings were 60 percent of the Lee family' 12 Oct 2024, 04:14
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Can someone help me with estimations here? I struggled a lot to get from 72/112 to 64%
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 18 Nov 2025
Posts: 105,355
Own Kudos:
778,078
 [1]
Given Kudos: 99,964
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,355
Kudos: 778,078
 [1]
In May Mrs Lee's earnings were 60 percent of the Lee family' 12 Oct 2024, 10:04
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
glagad
Can someone help me with estimations here? I struggled a lot to get from 72/112 to 64%
Show more

\(\frac{72}{112}*100=\)

\(=\frac{9}{14}*100=\)

\(=\frac{9}{7}*50=\)

\(=\frac{450}{7}=\)

\(=64.something\)
User avatar
sarthak1701
User avatar
Joined: 11 Sep 2024
Last visit: 16 Nov 2025
Posts: 110
Own Kudos:
50
Given Kudos: 18
GMAT Focus 1: 575 Q77 V81 DI78
GMAT Focus 1: 575 Q77 V81 DI78
Posts: 110
Kudos: 50
In May Mrs Lee's earnings were 60 percent of the Lee family' 12 Oct 2024, 10:32
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This felt too easy while some 655-level questions feel too hard lol :)

Let the family's total income for May be 100, Mrs. Lee's income is 60, and the rest of the family's income is 40.

In June, she earned 20% more, therefore she earned 72, while the rest of the family's income was same i.e. 40, total family income = 72+40 = 112.

Lee's income as a percent of family income = 72/112*100 = 450/7 = 64.2%. Ans. A
User avatar
GMATCoachBen
User avatar
Joined: 21 Mar 2017
Last visit: 18 Nov 2025
Posts: 465
Own Kudos:
2,719
Given Kudos: 210
Status:Professional GMAT Trainer
Affiliations: GMAT Coach
Location: United States (WA)
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 1: 760 Q50 V44
GMAT 2: 770 Q51 V44
GMAT 3: 770 Q50 V44
GMAT 4: 770 Q50 V45 (Online)
GMAT 5: 780 Q51 V48
Expert
Expert reply
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 5: 780 Q51 V48
Posts: 465
Kudos: 2,719
In May Mrs Lee's earnings were 60 percent of the Lee family' 30 Sep 2025, 18:33
Kudos
Add Kudos
Bookmarks
Bookmark this Post
glagad
Can someone help me with estimations here? I struggled a lot to get from 72/112 to 64%
Show more
glagad The answers are spread out enough (4% apart) that we can round a little:

I'd round to 70 / 110 = 7 / 11

1/11 ≈ 9%

7 * 9% = 63% ≈ 64%

(Note that rounding from 72 / 112 to 70 / 110 does not change the result much; it goes from 64.3% to 63.6%. A real-life example would be a basketball player makes 2 free throws, to go from 70/110 to 72/112; the denominator of 112 is big enough that it's not going to change the percentage much.)


Show Spoiler
Attachment:
GMAT-Club-Forum-vjz5zpqt.png
GMAT-Club-Forum-vjz5zpqt.png [ 58.61 KiB | Viewed 203 times ]
User avatar
GMATCoachBen
User avatar
Joined: 21 Mar 2017
Last visit: 18 Nov 2025
Posts: 465
Own Kudos:
2,719
Given Kudos: 210
Status:Professional GMAT Trainer
Affiliations: GMAT Coach
Location: United States (WA)
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 1: 760 Q50 V44
GMAT 2: 770 Q51 V44
GMAT 3: 770 Q50 V44
GMAT 4: 770 Q50 V45 (Online)
GMAT 5: 780 Q51 V48
Expert
Expert reply
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 5: 780 Q51 V48
Posts: 465
Kudos: 2,719
In May Mrs Lee's earnings were 60 percent of the Lee family' 30 Sep 2025, 18:35
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Vordhosbn
Number picking is the way to go here. We can assume family of two.

In May: 60, 40 - assume she made $60 and the other person $40 giving us 60%
In June she made 1.2 more giving us 72 and the other person still made $40. 72/112*100 ~ 64%
Show more
Vordhosbn Yes, this is a great method, and I would also pick 100 as the total for May.

Here's how we can organize it into a table and stay organized.


Show Spoiler
Attachment:
GMAT-Club-Forum-cqae9lri.png
GMAT-Club-Forum-cqae9lri.png [ 239.02 KiB | Viewed 198 times ]
User avatar
GMATCoachBen
User avatar
Joined: 21 Mar 2017
Last visit: 18 Nov 2025
Posts: 465
Own Kudos:
2,719
Given Kudos: 210
Status:Professional GMAT Trainer
Affiliations: GMAT Coach
Location: United States (WA)
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 1: 760 Q50 V44
GMAT 2: 770 Q51 V44
GMAT 3: 770 Q50 V44
GMAT 4: 770 Q50 V45 (Online)
GMAT 5: 780 Q51 V48
Expert
Expert reply
GMAT Focus 1: 775 Q87 V90 DI88 (Online)
GMAT 5: 780 Q51 V48
Posts: 465
Kudos: 2,719
In May Mrs Lee's earnings were 60 percent of the Lee family' 30 Sep 2025, 18:43
Kudos
Add Kudos
Bookmarks
Bookmark this Post
dimitri92
In May Mrs Lee's earnings were 60 percent of the Lee family's total income. In June Mrs Lee earned 20 percent more than in May. If the rest of the family's income was the same both months, then, in June, Mrs Lee's earnings were approximately what percent of the Lee family's total income ?

(A) 64%
(B) 68%
(C) 72%
(D) 76%
(E) 80%
Show more
C is a very common trap here:



In general, don’t forget that if one part of the total changes, the total also changes. A common error is to account for only one of the changes, not both the part and the total.

On this one, if we pick the number 100 for the total in May, we must make sure to put 112 for the new total in June.

Here are some other ones to try, with similar traps:

https://gmatclub.com/forum/of-the-3-600-employees-of-company-x-1-3-are-clerical-if-the-clerical-43660.html#p307338

https://gmatclub.com/forum/of-the-800-employees-of-company-x-70-percent-have-been-with-93778.html#p721534
https://gmatclub.com/forum/when-2-9-of-the-votes-on-a-certain-resolution-have-been-counted-128471.html#p1052792

More broadly, it's essential to build habits for proactive error prevention.

My students find this doc helpful: GMAT Habits for Proactive and Mindful Error Prevention: How to Dodge Common Traps (by Ben@GMATcoach.com)

I suggest making your own copy of this doc and adding to it, based on your own mistakes and insights.
User avatar
bot00078
User avatar
Joined: 08 Mar 2025
Last visit: 07 Nov 2025
Posts: 36
Own Kudos:
4
Given Kudos: 14
GMAT Focus 1: 345 Q70 V66 DI62
GMAT Focus 1: 345 Q70 V66 DI62
Posts: 36
Kudos: 4
In May Mrs Lee's earnings were 60 percent of the Lee family' 30 Sep 2025, 22:22
Kudos
Add Kudos
Bookmarks
Bookmark this Post

Show Spoiler
Attachment:
GMAT-Club-Forum-vdql9iw5.jpeg
GMAT-Club-Forum-vdql9iw5.jpeg [ 108.98 KiB | Viewed 164 times ]
User avatar
egmat
User avatar
e-GMAT Representative
Joined: 02 Nov 2011
Last visit: 18 Nov 2025
Posts: 5,108
Own Kudos:
32,883
Given Kudos: 700
GMAT Date: 08-19-2020
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 5,108
Kudos: 32,883
In May Mrs Lee's earnings were 60 percent of the Lee family' 08 Oct 2025, 05:50
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This is a classic percent problem that trips up a lot of students. The tricky part? You need to recognize that when Mrs. Lee's income increases but everyone else's stays the same, both her earnings AND the total family income change. Let me walk you through how to handle this.

Here's how to think about it:

Step 1: Understand what's happening

In May, Mrs. Lee earned 60% of the family's total income. That means the rest of the family earned 40%. In June, Mrs. Lee got a 20% raise on her May earnings, while everyone else's income stayed exactly the same. You need to find what percent of the new total her June earnings represent.

The key insight here: When Mrs. Lee's income goes up but the rest stays constant, the family's total income increases too. So you can't just add 20% to 60% and call it a day!

Step 2: Use concrete numbers

Let's make this easier by using actual dollar amounts. Since Mrs. Lee earned 60% of the total in May, let's say the family's total income in May was $100.

So in May:
  • Mrs. Lee: $60 (60% of $100)
  • Rest of family: $40 (40% of $100)
  • Total: $100

Step 3: Calculate June earnings

Mrs. Lee earned 20% more in June than in May:
\(20\%\) of \(\$60 = \$12\)

So Mrs. Lee's June earnings: \(\$60 + \$12 = \$72\)

Step 4: Find the new percentage

Now here's where students often slip up. The rest of the family still earned $40, so:

June family income:
  • Mrs. Lee: $72
  • Rest of family: $40
  • New total: $112

Mrs. Lee's percentage in June:
\(\frac{72}{112} = 0.6429 = 64.29\%\)

Approximately 64%

Answer: (A) 64%

Notice how Mrs. Lee's share only went from 60% to about 64%, not to 80%? That's because the denominator (total family income) increased along with her earnings.

Want to master these "changing base" percent problems? The complete solution on Neuron shows you the systematic framework that works every time, plus the common trap variations of this problem type and time-saving techniques. You can check out the step-by-step solution on Neuron by e-GMAT to understand the underlying pattern recognition approach. You can also practice with comprehensive solutions for other official questions here to build consistent accuracy on these problem types.

Hope this helps!
User avatar
adewale223
User avatar
Joined: 07 Oct 2022
Last visit: 15 Oct 2025
Posts: 113
Own Kudos:
72
Given Kudos: 45
Location: Nigeria
Posts: 113
Kudos: 72
In May Mrs Lee's earnings were 60 percent of the Lee family' 08 Oct 2025, 16:54
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Family income in May= x


Lee's income 3x/5

Rest of family 2x/5


In June

Lee's income = 120/100 X 3x/5



= 18x/25


Total income will now be 18x/25 + 2x/5


28x/25




Percent of Lee's income in June


18x/25 X 25/28x X 100


approx 64%

Answer A
   1   2 
Moderators:
Bunuel
Math Expert
105355 posts
Krunaal
Tuck School Moderator
805 posts