Hello!
First you have to find the probability of them happening separately
To find this you do the amount of favorable outcomes over the total amount of outcomes
Joey is only 1 kid and there are 12 total
This is a chance of 1/12
Chloe is 1 kid out of 11 now since Joey was already picked
This is a chance of 1/11
Zoe is 1 kid out of 10 since Joey and Chloe was already picked
This is a chance of 1/10
To find the probability of them happening separately you multiply them together
1/12 * 1/11 * 1/10 = 1/1320
The answer is C) 1/1320
Hope this helps!