Guess I'll give 'em a whirl.

Some months have 30 days, and some have 31. How many months have 28?

All of them.

A man gave one son 10 cents and another son was given 15 cents. What time is it?

As of this writing 2:45pm.

Is half of two plus two equal to 2 or 3?

3, I'd suppose.

EDIT: Ah, I get it. Tricky. That'd be 2.

Do they have a 4th of July in England?

Yes. It's just not a holiday, probably.

How many animals of each species did Moses take on the Ark with him?

Moses didn't go on the Ark. That would be Noah.

How far can a dog run into the woods?

A foot or so, I'd imagine, because after that he'd be running "in" the woods, rather than "into" them. Or perhaps halfway, because then he'd be running "out" of the woods.

Is it legal in Oregon to marry your widow's sister?

I'd hope not, seeing as you're all dead and creepified.

If a farmer has 5 haystacks in one field and 4 in another field, how many stacks would he have if he combined them in the center field?

1 big haystack.

What is it that goes up and down, but does not move?

I'd guess the sun?

I have in my hand only 2 U.S. coins which total 55 cents in value. One is not a nickel. What are the coins?

50 cent piece and a nickel... one isn't a nickel, but the other is.

A farmer has 17 sheep. All but 9 died. How many did he have left?

9

What is 30 divided by 1/2 plus 10?

70

You are a bus driver. The driver starts his route and picks up 20 people at the first stop. At the next stop, he picks up 12 more, and drops off 8. He then goes to the next stop, picks up 4, drops off 7. At the next stop, he picks up 15 and drops off 18. Now, here comes the tricky part. What color is the driver's eyes?

In my case, brown.

You have a face alarm clock. You set it for 9 in the morning, and you go to bed at 8 at night. Supposing you fall asleep right when you go to bed, how many hours of sleep will you get?

I'm not that familliar with face alarm clocks, but I'd guess only 1 since I'm not certain they are able to tell the difference between am and pm.