Good Riddles

Question: There are four men: Abe, Butch, Cam, and Dan. There are four hats: two white and two black. They each get a hat: Abe gets black, Butch gets white, Cam gets black, and Dan gets white. They don't know what hat color they have. Abe goes into a room so that no one can see his hat. The others line up in front of the door in the order Butch, Cam, and Dan (Butch can't see the others hats, Cam can see Butch's, and Dan can see Cam and Butch's hats). Whoever can figure out their hat color first wins $1,000. If they are wrong they are out of the running.

Which man can figure out his hat color without a doubt?

Question: I have memories, but none of my own,
whatever's on my inside is what is shown.
If I'm ever different it's because you changed me,
I feel like a decoration, here for you to arrange me.

What am I?

Question: Rob and Bob are arch enemies. They decide to have a fight to the death one day when a fairy appears. The fairy says it will give them both one wish. Bob wishes, "I wish for twice whatever Rob asks for."

What can Rob ask for to ensure he wins the fight?

Question: 16 06 68 88 ? 98.

What is the '?'?

Question: There is a farmer who has three sons. Nearing his death, he asked his three sons to find two objects that can fill the room he's in. The one who can deliver will be chosen as his heir. So the oldest son goes to the market to get hay while the middle son go get leaves. The youngest son goes to a shop and buys two things that he put in his pocket. The oldest son's hay only fills half the room, the middle son's leaves fills 2/4 quarters of the room, while the youngest fills the room with his two objects. Question: What are the two objects that the youngest son used to fill the room?