Question

Sari packs 2 mugs into a gift box she has 4 colors of mugs to choose from red white green blue how many combinations of two different color mugs can she pack into the box

Answer 1

10 different combinations

Answer 2

Combinations (Two we choose from four)
$C_4^2={4\choose 2}=\frac{4!}{2!*2!}=\frac{2!\cdot 3\cdot \not4^2}{2!\cdot \not2^1}=3\cdot 2=6$