The classes in common were lower division calculus (8 or 12 hours, depending if you took the condensed accelerated version), linear algebra (3 hours), and probability (3 hours).
Students could of course take more math electives, but you could get a CS degree with just 14 hours of math [2] [3] [4].
[1] https://www.cs.utexas.edu/sites/default/files/images/16-18%2...
[2] Discrete math is a requirement for CS, but not for math, so I didn't count it. If you include it, that raises the number of hours to 17. Either way, that's only a semester's worth of math.
[3] CS students are required to take 24 hours of upper division electives, many of which are math oriented, but based on this list, it'd still be possible to fill those 24 hours with non-math related topics: https://www.cs.utexas.edu/undergraduate-program/academics/cu...
[4] I realize that many classes in the core CS curriculum are math oriented, like algorithms, however this would not fulfill a math requirement. One couldn't pick up a minor in math based on the core curriculum alone and would need to deliberately add math electives.
Having been through both I can see the logic of both approaches.