do a straight in poker beat 3 of a kind?

The standard ranking of poker hands are:

Royal flush: Five cards in sequence and of the same suit, starting from the Ace down to the 10. Example: A♠ K♠ Q♠ J♠ 10♠ (Note: A Royal Flush is not a category of hand in and of itself, it is simply the highest-valued straight flush, and thus also the highest-valued hand. Since it is mentioned often in the context of hand rankings, it is worth noting in this list.)

Straight flush: Any five cards in sequence and of the same suit. Example: Q♦ J♦ 10♦ 9♦ 8♦

Four of a kind: A hand with four cards of the same rank. Example: 4♣ 4♦ 4♥ 4♠ 9♥

Full house: A hand with three cards of one rank and two of another. Example: 8♣ 8♦ 8♠ K♥ K♠

Flush: Five cards of the same suit. Example: K♠ J♠ 8♠ 4♠ 3♠

Straight: Five cards in sequence. (The ace can be considered higher than the king or lower than the two.) Example: 5♦ 4♥ 3♠ 2♦ A♦

Three of a kind: Three cards of the same rank. Example: 7♣ 7♥ 7♠ K♦ 2♠

Two pair: Two cards of one rank, two of another. Example: A♣ A♦ 8♥ 8♠ Q♠

One pair: Two cards of the same rank. Example: 9♥ 9♠ A♣ J♠ 4♥

High card: Also known as a "no pair" hand. The following example is considered "Ace high." Example: A♦ 10♦ 9♠ 5♣ 4♣

Yes

Yup.

Yes, it do.