Question

A ball will be drawn from a bag containing 20 balls numbered 1 through 20. If each ball is equally likely to be drawn, what is the probability that the number on the ball drawn will be even or less than 5?

Answer 1

Answer: 3/5

Step-by-step explanation:  

There are 20 balls, numbered 1 through 20.

Of these, 10 are even, 4 are less than five, and 2 are both even and less than 5.

So the probability is:

P(even or <5) = P(even) + P(<5) − P(even and <5)

P(even or <5) = 10/20 + 4/20 − 2/20

P(even or <5) = 12/20

P(even or <5) = 3/5