Maths probability help (5m)

This is the binomial distribution problem in probability.

Let the broad bean has their own no. ranged from 1 to 15. Then for exactly 14 of them to sprout, the following events are possible:

Bean 1 not sprout while others sprout
Bean 2 not sprout while others sprout
Bean 3 not sprout while others sprout

and so on until

Bean 15 not sprout while others sprout

So totally there are 15 possible events, each having a probability of 0.914 x (1 - 0.9) since we need 14 of them to sprout.

So the required probability is 15 x 0.914 x (1 - 0.9) = 0.3088