You can only unlock the chapter using a special code that we will send you via the Viber app. Receiving a message is free of charge and with no obligations.
My phone number:
Get a code
In compliance with the law, persons under the age of 15 can enter their phone number only in the presence of a parent or guardian.
4-character (Viber) code:
Check the received code
The page will be refreshed automatically in a few seconds.
An event organizer prepared 120 cups and 80 plates. Visitors used 81 cups and 70 plates. How many cups and plates were left clean at the end of the event?
The detailed solution steps are locked. Click on the blue button to unlock them.
Note: This problem has dynamic elements. This means elements such as numbers and consequently the step-by-step solution and the final answer may change overtime. Therefore, there may be a difference between a problem that is published online and the same problem exported into a PDF document.
Number of clean cups:
Number of clean plates:
To view the solution, you need to log in.
You must confirm your username (email address) to view the solution.
To ensure the proper functioning of the website, OpenProf uses cookies that do not store personal data. By continuing to use the website, you agree to cookies. Tell me more »
