Probability question explanation

[mathgeniusneedshelp]

The price at which the crude oil extracted from Alberta’s tar sands can be sold is determined by the “Brent Crude” price at which crude oil is traded. At a Brent Crude price of $60/barrel 42% of the oil in the tar sands can be extracted profitably.

(a) A market research company forecasts the Brent Crude price will be over $60/barrel next year with a probability of 0.9 and that it will be over $60/barrel the following year with a probability of 0.8. These two forecasts are independent of each other.

What is the probability that the Brent Crude price will be over $60/barrel either next year or the following year or both years?

 

[tkhunny]

Have you considered drawing a tree?

If p(price > $60/barrel) = 0.90, then what is p(price <= $60/barrel)?