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
