# Chapter 11 - Counting Methods and Probability Theory - 11.6 Events Involving Not and Or; Odds - Exercise Set 11.6 - Page 736: 53

$\frac{53}{142}$

#### Work Step by Step

The probability that an event E will not occur is equal to 1 minus the probability that it will occur. P(not E)= 1 - P(E) E: is in the Air Force or the Marines A = Neither in the Air Force nor the Marines P(is in the Air Force or the Marines.) = 1 - P( Neither in Air force nor in Marines) P( Neither in Air force nor in Marines) = $\frac{890000}{1420000}$ = $\frac{89}{142}$ P(is in the Air Force or the Marines) = 1 - $\frac{89}{142}$ = $\frac{142 - 89}{142}$ = $\frac{53}{142}$

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