Question

The number of cells in a growing fetus triple every 30 minutes. At 11:00 am there were 2cells at the moment the fetus began to grow. How many cells are there at 1:30 pm?

Answer 1

There are 2 and a half hours between 11:00 am and 1:30 pm. This is equivalent t o 5 periods of 30 minutes

cells | periods of 30 min

2 | 0 (11:00 am)

3*2=6 | 1 (11:30 am)

3*6=18 | 2 (12:00 pm)

3*18=54 | 3 (12:30 pm)

3*54=162 | 4 (1:00 pm)

3*162=486 | 5 (1:30 pm)