Waste less time on Facebook — follow Brilliant.
Discrete Mathematics

Rule of Sum and Rule of Product

Rule of Sum and Rule of Product: Level 2 Challenges



When we write the integers from 1 to 100, how many times does the digit 9 appear?

Which of the following expresses the correct formula for the number of unit squares with exactly 1 red side in an \( n \times n \) square with \( n \geq 2 \) ?

Find the number of \(2\) digit numbers whose digit sum is a perfect square.

If you take a \(3 \times 3 \times 3\) Rubik cube and break it up into the \( 3^3 \) cubes, how many cubes would have stickers on exactly \(2\) faces?

Bonus question: Can you generalize this for a \(N \times N \times N\) Rubik cube?


Problem Loading...

Note Loading...

Set Loading...