Question

What is the complement of event "At least 3 engines fail" (Hint: "at least 3 engines fail" is equivalent to "at most 1 engine work")

• A. At least 1 engines work
• B. At most 1 engines work
• C. At least 2 engines work
• D. At most 2 engines work

Answer 1

We are given the at least 3 engines fail is equivalent to at most 1 engine work.

So complement event of at most 1engine work is at least 2 engines work.

So complement event of at least 3 engines fail is equivalent to at most 2 engine work

Option C) is correct.