Answer:
352,716 juries of 10 people can be formed from 21 possible candidates
Explanation:
I am supposing that there are no roles in the jury, which means that the order in which the people are chosen is not important. So i calculate the number of possible juries using the combinations formula.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

10 people from a set of 21

352,716 10 person juries can be formed from 21 possible candidates