Math Word Problem come one come all to help please :)?

Ink Inc., a publishing firm, offers its 899 employees a cafeteria approach to benefits, in which employees can enroll in the benefit plan of their choice. Seven hundred thirteen employees have health insurance, 523 have dental insurance, and 489 have both health and dental insurance. (a) What is the probability p that one of the employees has either health or dental insurance? p = (b) What is the probability p that one of the employees has health insurance but not dental insurance? p = if you can get this write i will give you best answer if you could show how you got the answer that would be really cool to. thanks for the look and maybe the help
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489 have both health and dental insurance, therefore 713-489 = 224 have just health insurance and 523-489 = 34 have just dental insurance. Therefore 899-489-224-34 = 152 have neither health nor dental insurance. (a) The probability that one has either health or dental insurance is (224+34+489)/899 = .831. (b) The probability that one has health insurance but not dental insurance is 224/899 = .249.
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