I can give you a link https://youtu.be/aUy-_WnEV30 . I hope this answers your problem, and gives you greater insight. Sorry I couldn't do more :(
1/3 chances that it will be a girl or a boy because their is only a 50/50% and their is 3 children
The answer for 3/16 in decimal is 0.1875
Hope this helps :)