*If jurors are selected randomly from an adult population, find the probability that all 12 jurors are white when the population is*

a) 90% white

b) 50% white

a) 90% white

b) 50% white

**WHAT IS CONFUSING ME:**

How in the world can a person figure this out when one doesn't know what the city's population is?

THere's an example of a very similar problem in my book that says that if 50% of a town's population were female, and 50% male, the probability that the jury would be all male is only .00024 and that they somehow determined this from the fact that there are only 4096 possible ways that a jury of 12 can be composed. I have no idea what they are talking about.

Can anyone should some light? If so, PLEASE DO.