INTEGERS (3)

1. Initially, Jane is in a lift on the 12^th floor of a building. Then the lift moves down 5 floors. On which floor is Jane now?
2. A submarine dived 72 m into the ocean. Then it went up by 37 m. How far is it from the surface of the sea?
3. The price of a share of a company on Monday was 85 sen. On Tuesday, it went up by 7 sen. On Wednesday, it fell by 9 sen. What is the price of the share at the end of Wednesday?
4. A bird is flying at a height of 45 m above sea level. Then it flies up another 10 m before flying down 18 m. What is the bird’s height above sea level now?
5. Azlyn’s office is on the 13^th floor. She went down 9 floors to go to the cafeteria. Then, she went up 6 floors to meet her friend. At which floor is her friend’s office?