Question

Consider an urn. That’s right, an urn. Inside are—you guessed it—different kinds of balls. There are 4 pink balls, 6 purple balls, and 5 balls with Knachel’s face painted on them. If you draw balls from the urn three times, replacing each after it’s drawn, what’s the probability that you’ll get 3 straight Knachels?

Answer 1

An urn contains 4 pink balls, 6 purple balls and 5 balls with knachel's face painted on them.

Therefore, total number of balls in the urn = 15

3 balls are drawn from the urn with replacement.

The probability of getting 3 straight knachels is

P(3 knachels) = P(getting knachels in all 3 draws)

                       = (5 / 15) * (5 / 15) * (5 / 15)

                       = (1 / 3)³

                       = 0.037

Therefore, the probability that you'll get 3 straight knachels is 0.037