Three coins are tossed. Find prob. that at least two are....

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1) Three coins are tossed. What is the probability that at least two come up heads?

I'm having a brain freeze and for some reason cannot determine whether I am answering this problem correctly or not.

I got 1/8. I multiplied the probability of each coin landing heads up, so 1/2 times 1/2 times 1/2. Is this right?

2) Two six-sided dice are rolled. Find the probability that exactly one die shows a five.

I simply answered 1/6, but is there something slightly more complex when it says EXACTLY one die shows a five?

Thanks so much!!!!!
 
here is the sample space ...

HHH
HHT
HTH
THH
HTT
THT
TTH
TTT

"at least" 2 heads means either 2 or 3 heads are the result

P(at least 2 heads) = 1/2
 
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