As part of a promotion, both you and your roommate are given free cellular phones from a batch of 10 phones. Unknown to you, five of the phones are faulty and do not work. Find the probability that...

As part of a promotion, both you and your roommate are given free cellular phones from a batch of 10 phones. Unknown to you, five of the phones are faulty and do not work. Find the probability that one of the two phones is faulty.