GMAT Practice Questions | GMAT Rates Q8

Work Time | Rates | GMAT Sample Questions

A GMAT quant practice question in rates. A word problem in work time. Your ability to convert information given in words to mathematical expressions and equations is the gist of what is tested in any GMAT word problem. A medium difficulty, GMAT 650 level, quantitative reasoning sample question.

Question 8: A can complete a project in 20 days and B can complete the same project in 30 days. If A and B start working on the project together and A quits 10 days before the project is completed, in how many days will the project be completed?

  1. 18 days
  2. 27 days
  3. 26.67 days
  4. 16 days
  5. 12 days

Get to 705+ in the GMAT


Online GMAT Course
@ INR 6000


Video Explanation


GMAT Live Online Classes


Starts Sun, Mar 3, 2024


Explanatory Answer | GMAT Work Time

A can complete a project in 20 days. So, A will complete \\frac{1}{20})th of the project in a day.
B can complete a project in 30 days. So, B will complete \\frac{1}{30})th of the project in a day.

Let the total number of days taken to complete the project be 'x' days.
The value of x is the answer to the question.

B worked all x days. However, A worked for (x - 10) days because A quits 10 days before the project is completed.

In a day, A completes \\frac{1}{20})th of the project.
Therefore, A would have completed \\frac{x - 10}{20})th of the project in (x - 10) days.

In a day, B completes\\frac{1}{30})th of the project.
Therefore, B would have completed \\frac{x}{30})th of the project in x days.
∴ \\frac{x - 10}{20} + \frac{x}{30}) = 1
\\frac{3(x - 10) + 2x}{60}) = 1
3x - 30 + 2x = 60
5x = 90 or x = 18

Choice A is the correct answer.



GMAT Online Course
Try it free!

Register in 2 easy steps and
Start learning in 5 minutes!

★ Sign up

Already have an Account?

★ Login

GMAT Live Online Classes

Next Batch Mar 3, 2024

★ GMAT Live Info

GMAT Rates Videos On YouTube


GMAT Sample Questions | Topicwise GMAT Questions


Work @ Wizako

How to reach Wizako?

Mobile: (91) 95000 48484
WhatsApp: WhatsApp Now
Email: learn@wizako.com
Leave A Message