Principle of Inclusion and Exclusion

Principle of Inclusion and Exclusion: Level 1 Challenges


In a town of 50,000 people,
28,000 people read NanJing Morning News,
23,000 people read NanJing Evening News, and
4,000 people read both.

How many people read neither?

Katie is teaching a class of thirty pupils, of which fourteen are girls. She knows that there are twenty-two pupils who are right-handed.

What is the minimum number of girls who are right-handed in this class?

How many positive integers less than or equal to 60 are divisible by 3, 4, or 5?

At a construction site, Jorge is in charge of hiring skilled workers for the project. Out of 80 candidates that he interviewed, he found that

  • 45 were painters,
  • 50 were electricians,
  • 50 were plumbers,
  • 15 had skills in all three areas, and
  • all of them had skills in at least one of these areas.

If he hired everyone who was skilled in exactly 2 areas, how many candidates were hired?

For the integers from 1 to 1000, how many multiples of 9 are also multiples of 6?


Problem Loading...

Note Loading...

Set Loading...