Question

An anti-aircraft gun can take a maximum of four shots at any plane moving away from it. The probabilities of hitting the plane at the 1 st, 2 nd, 3 rd and 4 th shots are 0.4, 0.3, 0.2 and 0.1 respectively. What is the probability that at least one shot hits the plane?

• A. 0.6976
• B. 0.3024
• C. 0.72
• D. 0.6431

Answer 1

Answer: (A)

0.6976

Answer 2

Probability that at least one shot hits the plane $=1-P$ (none of the shot hits the plane) $=1-0.60.7\times 0.8\times 0.9$ $=1-0.3024$ $=0.6976$