Assume P(Red Light) = .40
and P(Green Light) = .60
.
This is not answerable as stated; at least, not without assuming independence and without a clearer statement of what the probability is out of (the reference class: is it out of all ways in which the five pulls could turn out, or only the ones in which there are three green?)
If we're willing to assume indendence and that we're talking about any combination of 5 pulls, then the desired outcome is the probability that:
This is the same as
The probability of getting 2 green lights of 4 can be calculated using the binomial probability distribution and is
choose(4,2) * .4^2 * .6^2
The probability of the fifth being green is .6. So the whole probability is
choose(4,2) * .4^2 * .6^2 * .6 = choose(4,2) * .4^2 * .6^3