# The percentage of smokers among females is found to be 1%. If 5 females are randomly chosen what's the probability that all are smokers?

### 1 Answer

- PuzzlingLv 74 weeks ago
We have to assume the probability of each person being a smoker is independent of the others and always 0.01 for females.

The probability of the first being a smoker is 0.01

The probability of the second being a smoker is 0.01

The probability of the third being a smoker is 0.01

The probability of the fourth being a smoker is 0.01

The probability of the fifth being a smoker is 0.01

The probability of all being smokers:

0.01 * 0.01 * 0.01 * 0.01 * 0.01

= 0.0000000001

Or if done using fractions:

1/100 * 1/100 * 1/100 * 1/100 * 1/100

= 1/10,000,000,000

Answer:

0.0000000001 (or 1 in 10 billion)

P.S. The actual rates of smoking among adult females in the U.S. is still about 12%, so the result wouldn't be actually that low in the real world. Globally the rates are about 9% of adult females.