Answer
180
Work Step by Step
As we are required to calculate the ways to select courses, and order does matter, we need to use both permutations and combinations. Since the order of classes matters, there are ($3_{P_{3}}$) ways to order the 3 different types of classes. There are also ($2_{C_{1}}$) ways to choose math, ($3_{C_{1}}$) ways to choose science, and ($5_{C_{1}}$) to choose social studies.
Hence the ans = $3_{P_{3}}$*$2_{C_{1}}$*$3_{C_{1}}$*$5_{C_{1}}$ = 6*2*3*5=180
