Question

The probability of a radar station detecting an enemy plane is 0.65 and the probability of not detecting an enemy plane is 0.35. If 100 stations are in use, what is the expected number of stations that will detect an enemy plane?

100
98
65
none of these choices

Answer 1

65

Explanation:

All you have to do is size the number up by 100. If 1 has a .65% success rate, that would mean it would now be 65% for 100.