Math Problems

Drawing a "venn diagram" helps too. Start from the middle and work outwards

Seconding this.

Flawed method... that worked?

 Spoiler

I made 3 circles in a box. The box represents everyone. Those in the box and not a circle get nothing. Each circle represents a color. Each circle over-laps the other two circles.

Where the Red and White circles overlap, label "15". Red and Blue 20, Blue and White 25. These numbers are given.

Since 45 people got red, one circle, including the bits shared with other circles, must be 45. You have 15+20=35 already accounted for in the Red circle, so you can conclude that 45-35=10 people got exclusively red. Repeat for the two remaining circles.

My end result was 10 with no tokens. When I reread the problem and post, I saw "5 with all three". 10-5 = 5.

How did that work when I pushed subtracting 5 to the end and how did you guys get 20?