At Mike's favorite coffee shop, the coffee of the day is either a dark roast, a medium roast, or a light roast. From past experience, Mike knows that the probability of the coffee being a light roast is 0.15 and the probability of the coffee being a dark roast is 0.25. What is the probability of the coffee of the day not being a light roast or a dark roast on the next day that Mike visits the coffee shop?

Step-by-step explanation:

Given

Probability that coffee being a light roast is P (1) = 0.15

Probability that coffee being a dark roast is P (2) = 0.25

considering the event being independent of each other

Probability that coffee not being a light roast or dark roast is given by

P (not being dark or light roast) = 1-P (1) - P (2)

P (not being dark or light roast) = 1-0.15-0.25

P (not being dark or light roast) = 0.6