Good Riddles

Question: I have all of your knowledge but could fit in your hands.

What am I?

Question: I join you in battle, fist clenched tight.
We pound three times with all our might.
If my rival decides he will sign for peace;
I'll crush him, and the fight will cease.
But if he lays his hand down flat;
I'll suffer defeat, that is that.

What am I?

Question: I build bridges of silver and crowns of gold.Who am I?

Question: There are 1600 people sitting around a circular table. The first person (person 1) has a sword and kills the second person then hands it to the next alive person (in this case person 3). Person 3 stabs person 4 and gives the sword to person 5. This goes on until person 1499 kills person 1500. Then person 1 kills person 3 and so on. This is repeated until there is only a single person remaining.

Who remains in the end?

Question: Nathan has math 4 times a week. If he has math 8:00 Monday, 9:20 on Tuesday, 10:40 on Wednesday, and 1:20 on Friday, when does Nathan have math on Thursday?