<h3>
Answer: 3/5</h3>
Work Shown:
3 blue + 3 red = 6 pens that are either blue or red
4 black + 3 blue + 3 red = 10 pens total
6/10 = 3/5 is the probability of selecting either blue or red
3/5 = 0.60 = 60%
And we are given that
and want to find the value of x. Set f(x) to 16 and we get the equation:

Subtract both sides by 4

Divide both sides by 2

This is the answer. Let me know if you need any clarifications, thanks!