Let X denote the number of hours you study during a randomly selected school day. The probability that X can take the values x, has the following where k is come unknown constant.

What is the probability of studying at most two hours?

0.55

P(at most two hours) = P(X<=2)

P(X<=2) = P(X=0) + P(X=1) + P(X=2)

              = 0.1 + k + 2k = 3k + 0.1

              = 3(0.15) + 0.1

              = 0.55