Question

In a group of 120 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?

Answer 1

Person having age less than 20=120-90=30

• |S|=120
• |E|=30

`\\ \tt\hookrightarrow P(E)=(|E|)/(|S|)`

`\\ \tt\hookrightarrow P(E)=(30)/(120)`

`\\ \tt\hookrightarrow P(E)=(1)/(4)`

Answer 2

0.25

Explanation:

Number of people whose age is less than 20 is given by

120 - 90 = 30

Probability P that a person selected at random from the group is less than 20 is gieven by

30 / 120 = 0.25