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What is the prime factorization of 195

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?

Find the condition that the zeros of the polynomial f(x) = x^3+3px^2+3px+r may be in a.p.