Last visit was: 29 Apr 2026, 17:53 It is currently 29 Apr 2026, 17:53
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bismuth83
User avatar
DI Forum Moderator
Joined: 15 Sep 2024
Last visit: 01 Aug 2025
Posts: 714
Own Kudos:
3,161
 [31]
Given Kudos: 441
Expert
Expert reply
Posts: 714
Kudos: 3,161
 [31]
7
Kudos
Add Kudos
23
Bookmarks
Bookmark this Post
User avatar
Bismuth83
User avatar
DI Forum Moderator
Joined: 15 Sep 2024
Last visit: 01 Aug 2025
Posts: 714
Own Kudos:
3,161
 [4]
Given Kudos: 441
Expert
Expert reply
Posts: 714
Kudos: 3,161
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
napolean92728
User avatar
CAT Forum Moderator
Joined: 13 Oct 2024
Last visit: 09 Apr 2026
Posts: 278
Own Kudos:
94
 [2]
Given Kudos: 233
Status:Death is nothing, but to live defeated and inglorious is to die daily.
Posts: 278
Kudos: 94
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
egmat
User avatar
e-GMAT Representative
Joined: 02 Nov 2011
Last visit: 27 Apr 2026
Posts: 5,632
Own Kudos:
33,438
 [2]
Given Kudos: 707
GMAT Date: 08-19-2020
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 5,632
Kudos: 33,438
 [2]
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Let me walk you through both ratios step by step.

Key Idea: For each ratio, figure out how many 'batches' you can make before running out of either powder. The powder that runs out first is the limiting factor.

Ratio A (Column A): 3g of X to 2g of Y

Each batch uses 3g of X + 2g of Y = 5g of alloy per batch.

How many batches can X support? 90 / 3 = 30 batches
How many batches can Y support? 80 / 2 = 40 batches

X runs out first (30 < 40), so X is the limiting factor. We can only make 30 batches.

Total alloy from Ratio A = 30 x 5 = 150 grams (Row 2)

Sanity check: This uses 90g of X (all of it) and 60g of Y (within the 80g supply). Works perfectly.

Ratio B (Column B): 11g of X to 10g of Y

Each batch uses 11g of X + 10g of Y = 21g of alloy per batch.

How many batches can X support? 90 / 11 = 8.18 → only 8 full batches
How many batches can Y support? 80 / 10 = 8 batches

Both powders allow exactly 8 batches (Y is the binding constraint since we can't do a partial batch of X either).

Total alloy from Ratio B = 8 x 21 = 168 grams (Row 5)

Sanity check: This uses 88g of X (within 90g) and 80g of Y (all of it). Works perfectly.

Answer: Row 2 for Column A (150 grams) and Row 5 for Column B (168 grams)

The core technique here is simple: divide each supply by the amount needed per batch, take the smaller whole number (that's your limiting factor), then multiply by the total grams per batch. This 'limiting reagent' concept shows up frequently in GMAT ratio problems.
Moderators:
Math Expert
109975 posts
498 posts
212 posts