Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Which country gets ill every time?

You are on your way to visit your Friend, who lives at the end of the hill. It is his birthday, and you want to give him the cakes you have made. Between your house and his house, you have to cross 5 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake. How many cakes do you have to leave home to make sure that you arrive at a friend's house with exactly two

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I add 5 to 9 and get 2. The answer is correct, so what am I?

What brings you down but never up?

What has to be broken before you can use it?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

What jumps when it walks and sits when it stands?

I am quite hot but become too cold if you remove the first two letters. What am I?