The dog can jump over his dog house.

The match.

c – The weight doesn’t change since it’s a closed system.

I hesitated to add this because it’s poorly worded, ambiguous and the answer could be almost anything. I prefer teasers with a single answer, but there you go.

If you came up with a different answer and can explain how you did it, don’t think you’re wrong. It’s probably just as valid. Feel free to share yours in the comments.

My answer for the first number is 2.

Here’s how I got it.

The generic rule for a number in the sequence is: 2^{^(n – 1)} + 1, where n is the position in the sequence.

Note: The teaser doesn’t specify the position of 17. In this case, it’s fifth.

Position 1: (so n = 1) is 2^{^(1 – 1)} + 1 = 2

Position 2: 2^{^(2 – 1)} + 1 = 3

Position 3: 2^{^(3 – 1)} + 1 = 5

Position 4: 2^{^(4 – 1)} + 1 = 9

Position 5: 2^{^(5 – 1)} + 1 = 17

For the curious, the next 5 numbers of the sequence would be:

Position 6: 2^{^(6 – 1)} + 1 = 33

Position 7: 2^{^(7 – 1)} + 1 = 65

Position 8: 2^{^(8 – 1)} + 1 = 129

Position 9: 2^{^(9 – 1)} + 1 = 257

Position 10: 2^{^(10 – 1)} + 1 = 513

It depends. Usually, math has one right answer, but in this case, the order of operations can get a little quirky.

There are two ways to solve this. First, like so:
48 / 2 × (9 + 3) = ?
48 / 2 × (12) = ?
24 × 12 = 288

But another, arguably valid way is:
48 / 2 × (9 + 3) = ?
48 / 2 × (12) = ?
48 / 24 = 2

Thanks to KnowYourMeme for providing a great overview on this one. Math StackExchange has more discussion.

Eat (8) flush (plus) to (2) my nose (minus) tree (3) times (times) for (4) they buy dead by (divided by) too (2).

There are two answers depending on whether you calculate as you read or calculate the entire solution at the end.
8 + 2 = 10, – 3 = 7, x 4 = 28, / 2 = 14
or
8 + 2 – 3 x 4 / 2 = 10 – 6 = 4