JAMB 2013 · UTME · Q47

In how many ways can a student select 2 subjects from 5 subjects?

Worked solution (try it first)

The order of the two subjects doesn't matter, so this is $^5C_2$ .
$^nC_r = \dfrac{n!}{r!\,(n - r)!}$ , so $^5C_2 = \dfrac{5!}{2!\,3!}$ , option A.