1 Language 2 Computer 3
Interchangeable position of language and computer
Three spaces
Mathematics precedes physical education class, and mathematics comes first.
① Mathematics and physical education are not together, mathematics is in 1, and the computer has two choices; Mathematics is in 2, and the computer has the choice of 1.
(3) Mathematics and physical education together, * * * three possibilities.
So there are 2×2×3= 12 kinds of a * * *.