5.11 Declan, Emily and Farid each intend to start their own business after leaving college. Declan wants to start a computer software company, Emily intends to open a recruitment agency, and Farid would like to launch a graphic design business. According to available evidence 60 per cent of computer software companies, 75 per cent of recruitment agencies, and 80 per cent of graphic design businesses fail within their first trading year. What is the probability that:

(a) The businesses that Declan, Emily and Farid start all stay in operation for at least a year?

(b) The businesses that two of them start are still trading after a year?

(c) All three businesses fail within a year?