Cisco Oracle and Google all have earnings reports coming out

Cisco, Oracle, and Google all have earnings reports coming out next week. Each company will either report a profit or a loss. Theres a 65% chance that Cisco will report a profit, a 30% chance that Oracle will report a profit, and a 90% chance that Google will report a profit. Assume that whether one company reports a profit is independent of whether any other company does.

1. What is the probability that Oracle reports a loss? [Hint: Rule of complement.] answer = .70

2. What is the probability that none of the three companies report a profit? [Hint: independence. All three companies report losses.] answer=0.0245

3. What is the probability that at least one of the three companies reports a profit? [Hint: The event in part (c) is the complement of the event in part (b).]

I just need help answering part three. please show work thank you!

Solution

3. What is the probability that at least one of the three companies reports a profit?

for part b) you already got

P(All three companies report losses)=0.0245

As indicated in hint , you just need to find it\'s complement to solve part 3) so just subtract 0.0245 from 1

P(at least one of the three companies reports a profit)=1-P(All three companies report losses)=1-0.0245=0.9755

Hence answer is 0.9755