in a group of 100 people , 90 have an age of more 30 years , and the others have an age of less than 20 years . if a person is selected at random from this group , what is the probability the person ' s age is less than 20 ?
n0 = 100.0
n1 = 90.0
n2 = 30.0
n3 = 20.0
n4 = 20.0
t0 = n0 - n1
answer = t0 / n0
print(answer)