A spinner with 12 equally sized slices has 4 blue slices, 3 red slices, and5 yellow slices. The dial is spun and stops on a slice at random. What is the probability that the dial stops on a blue or red slice?

There are 12 possible slices that it can stop on...it has 4 chances of stopping on a red one and 3 chances of stopping on a red one, so it has 7 out of 12 chances of stopping on a red or blue one (or 7/12). 7/12=58.33%