Question

The probability of a single radar station detecting an enemy plane is 0.75 and the probability of not detecting an enemy plane is 0.25. How many such stations are required to be 98% certain that an enemy plane flying over will be detected by at least one station?

Answer 1

This was a long time ago so i am assuming you dont need help anymore! :) If you do tell me! :) I will be glad to help you!

Explanation:

Answer 2

Atleast 3

Explanation:

P(atleast 1) = 1 - P(none)

1 - (0.25^n) 》 0.98

0.25^n 《 0.02

Use trial method:

At n=3, 0.25³ = 0.015625