The three kinds of levers are the:
A) First-class lever - Like a seesaw, the fulcrum is in the middle. The input force is on one side and the output force comes out on the other side of the fulcrum.
B) Second-class lever - This one is like a wheelbarrow. The fulcrum is all the way at the end, and you PULL upon the other end so the middle (where the bucket is) gets lifted up also.
C) Third-class lever - The third class lever is like the second, but the input force is not at the end. The fulcrum is at one end, and on the other end is the output force. Its like the forearm of a human, our elbow is the fulcrum while you grip things with hand means you life some weight that is load and the arm is where you feel some effort being applied..