Question

select the correct answer. a color palette at a paint store has 6 shades of blue. kelsie is choosing 2 shades of blue to paint her room. how many pairs of colors can she pick from the color palette? a. 12 b. 15 c. 30 d. 720

Explanation:

Step1: Use combination formula

$C(n,k)=\frac{n!}{k!(n - k)!}$, here $n = 6$, $k=2$.

Step2: Calculate factorials

$C(6,2)=\frac{6!}{2!(6 - 2)!}=\frac{6\times5\times4!}{2\times1\times4!}=15$

Answer:

B. 15