As 100 students entered the auditorium they were each given a prize. if every 6th student received a pencil and every 9th student received a notebook, how many participants received both pencil and notebook?

5 students got both a pencil and a notebook

Step-by-step explanation:

What I did was to know which multiplication table I knew better and not do that one. So, I already have 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99

Then I matched it with the 6's.

6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102

(This may not be the official method but I found this method the easiest)

So therefore your answer would be 5 students.