Of all mortgage foreclosures in the United States, 48% are caused by disability. People who are injured or ill cannot work—they then lose their jobs and thus their incomes. With no income, they cannot make their mortgage payment and the bank forecloses.

Source: http://www.ricedelman.com 06.11.02 Given that 20 mortgage foreclosures are audited by a large lending institution, find the probability of the following:

a. Five or fewer of the foreclosures are due to a disability.

b. At least three foreclosures are due to a disability.