Cells divide at different rates. The fastest bacteria can divide every 20 minutes. No wonder you can feel sick with food poisoning within hours of eating undercooked food! On the other hand, some nerve cells in your body do not divide much at all. The nerve cells in a 100-year old person could be close to 100 years old.

In november 1987, a massive iceberg broke loose from the antartic ice mass and floated free in the ocean. the chunk of ice was estimated to be 98 mi long, 25 mi wide, and 750 ft thick. a typical backyard swimming pool contains about 24,000 gallons of water. how many of these pools could you fill from the water in this iceberg? (assume the iceberg is a rectangular solid of the above dimensions and consists of water only). express answer in scientific notation.