Execute multiple packages from single package based on some condition??

Can we call multiple child packages from single Execute package task?. It should call child packages based on condition.

i have created 3 simple child packages called A, B, C respectively.

i have taken one user varibale called Event

Now

1. If Event is A, i need to call child package A

2. if Event is B, i need to call child package B

3. if Event is C, i need to call child package C.