<p>Adding on what was already said above:</p>
<p>the 20 series covers more material but if you’ve taken AP calc, both should be manageable. To give you an idea of what I mean, I took regular calc in high school and moved onto math 20A, and found that much of the material overlapped with what I learned in high school. I imagine it would only overlap more with AP material, so moving on to 20B should be okay, and 10B even more so.</p>
<p>Depends on your major. If you are sure you’ll never do something science/engineering related that will require the 20 series then 10 will be fine… I admit am a bit biased here… I took the 20 series because I was undeclared and it would allow me more major options because i was looking mostly at sciences</p>