For question below, first decide whether the situation is arithmetic or geometric, then solve accordingly.

The Chinese zodiac associates years with animals, based on a $12-$year cycle. Samu was born in $1962$, the Year of the Tiger. He lives in Finland, which celebrated its centennial in $2017$ . Did Finland gain its independence in the Year of the Tiger?

For question below, first decide whether the situation is arithmetic or geometric, then solve accordingly.

A scientist puts six bacteria, which multiply at a constant rate, in a Petri dish. She records the number of bacteria each minute thereafter. If she counts $324$ bacteria $20$ minutes later, at what rate are the bacteria reproducing?

For the series given below, decide whether it is arithmetic or geometric, then find the sum.

$\sum _{n=1}^6(-1{)}^{n-1}(2{)}^n$