“The probability of going into recession is 25% in any given year. Determine the the prob of recession in 1 out of 4 years & determine the expected number of recessions that occur in 4 years” The answer is 42% and 1 recession. but how do we get there??

Binomial thingymejob n!/(n-x)!x! * p^x * (1-p)^(n-x)

not sure how to determine the expected number of recessions though

(4!/(3!*1!))*(.25)^1*(.75)^3=42.19% Number of recession = (1/4)*4=1