Two ways of growing

A plant part grows by two rules. Under the arithmetic rule it adds the same weight each day. Under the geometric rule it doubles each day. You will build the two lists and compare them.

The idea. Both start at $3\ \text{g}$. The arithmetic part gains $3\ \text{g}$ a day. The geometric part doubles every day.

Your tasks.

1. Set arithmetic to the weight on each of the days 0 to 4 under the arithmetic rule.
2. Set geometric to the weight on each of the days 0 to 4 under the geometric rule.
3. Set first_day to the first day on which the geometric weight is larger than the arithmetic weight.