Not necessarily. For example, at UCB, the history major needs 12 courses, and the math major needs 13 courses (though many math majors are exempt from 2 of them which are frosh level calculus). There is one possible overlap course (history of math). So that makes 22 to 25 courses out of the usual 32 taken in 8 semesters. The usual general education requirements take 9 courses, but 1 to 3 are covered by the majors, and 0 to 2 English composition may be covered by AP credit, leaving 4 to 8 courses beyond the major.
So the student in this case needs a total of 26 to 33 courses to cover both majors and the usual general education, which should be doable in 8 semesters with 4 courses per semester (with one overload semester in the maximum case of 33 courses).