The way my freshman son explained it to me is he has 3 undergraduate years left with a maximum of 5 courses each semester. (He plans to complete his remaining 4 Humanities and Soc Science distribution credits using some combination of the 2 winter sessions and 2 summer sessions offered every year, leaving just courses in the 3 majors for the school year sessions.) Not counting twice any required courses used for more than one major and not reducing it for any elective courses that may apply to more than one major, he has left to complete-
Math: 2 math required,
3 math electives
Physics: 2 recommended math courses
4 required physics courses
3 elective physics courses
2 required labs (each worth 1/2 course)
CS: 5 required cs courses
2 elective cs courses
Total: 23 courses
I did not come up with this plan and am hoping once he gets major advisors they will make sure this is either a plan they support or will get him him to alter his plan. His plan may also change along the way since he is only a freshman and has not yet been involved in research. I am going to let him know the concerns raised here.
He does have credit for a statistics course from his AP score, but I agree he should plan to take a probability course and maybe another statistics course.