Probability assistance

I have 2 questions:

1. When determining the probable outcome with the "cyclists" as an example:

If there are 469 total "frequencies" and we want to know the probability that those between the ages of 50-59 (60 frequency) won't be participating, you calculate this how???

I approached this by dividing 60/469 = 0.128 which is incorrect

2. I am confused when it comes to understanding "mutually exclusive."

Given P(A )= 0.72 , P(B) =0.81, P(A or B) = 0.66

I arrive at 0.66 = 0.81 + 0.72 - P(A and B)

0.66 = 1.53 - P(A and B)

P(A and B) = 1.53 - 0.66

P(A and B) = 0.87

Why is this NOT mutually exclusive?