Assume that a society consists of two types of workers. For type A, 3 million workers lose their jobs each year, and each one takes a year to find a new one. For type B, 36 million workers lose their jobs each year (3 million per month), and each takes one month to find a new job. Thus, at any given time, 6 million are unemployed in this economy.

a . How many "spells" of unemployment occur each year in this economy?

b . What percentage of the "spells" are only one month long?

c . If you take all the workers unemployed each year and multiply each by the length of his or her unemployment "spell," how many "months" of unemployment would there be in this economy each year?

d . of all the "months" of unemployment, how many are accounted for by the workers unemployed a year at a time.