Answer:
84
Step-by-step explanation:
Combinations
nCr
n (objects) = 9
r (sample) = 3
9C3
n! / r! (n – r)!
9! / 3! (9 – 3)!=
9! / (3! * 6!)=
9*8*7*6!/ (3! * 6!)=
6! cancels out
9*8*7/3*2*1=
3*4*7=
12*7=
84
we can see that
the given curve is parabola
so, firstly we will find vertex
vertex is (4,0)
we can write equation of parabola

now, we can plug values
and we get

we can also write it as
.............Answer
The answer is .48 cents per sock .96 cents per pair