answer the question in/within thirty minutes

Dear native English speakers,
I have some questions.

Q1 Would (a) and (b) have the same meaning?
(a) The students must answer all the questions in thirty minutes.
(b) The students must answer all the questions within thirty minutes.

Q2 Would both be used? If so, is there any difference in meaning between them?
(a) It may snow tonight.
(b) It may be snowing tonight.

Q3 Would all the sentences be used with almost the same meaning?
(a) Let's go to Emily's house now.
(b) Let's go to Emily's home now.
(c) Let's go to Emily's place now.
(d) Let's go to Emily's now.
(e) Let's visit Emily's house.
(f) Let's visit Emily's home.
(g) Let's visit Emily's place.
(h) Let's visit Emily's.
(i) Let's visit Emily.

Thanks in advance.
Hirashin

#1: No. "A" sounds like 30 minutes from now is when you're supposed to start answering, "B" sounds like a time limit to actually answering the question.

#2: Yeah, they would both be used, and they have the same meaning.

#3: Yes, those are all roughly the same.

On number 3 of course the sentences that don't include the word now can of course leave the time as an undecided where now means right away. Also for (i) if Emily is in the hospital etc saying "Let's visit Emily" means you will be going to the hospital and not her house.