There are 6 choose 3 possibilities (combinations).
6C3 = 6!/(6-3)!3!
= 6•5•4/(3•2•1)
= 120/6
= 20
With 20 possibilities, there is a 1 in 20 chance that she will choose her favorite three.
The answer is Option C. 1/20.
Okay so

.
First, we make 16 a fraction:

Then, we make

a improper fraction:

Now, we multiply

by

:

Finally, we simplify

:

.
Your answer is

.
Hoped I helped. :)
I got the decimal form where x= 0.817395
if that's wrong then sorry
cos(3x) = cos(2x+x)
= cos(2x) cos (x) -sin(2x)sin(x)







