Answer:
D 81
Step-by-step explanation:
It is not prime. It can be divided by a number other than 1.
Answer:
The 21st term is 137.
Step-by-step explanation:
Arithmetic progression:
In an arithmetic progression the difference between consecutive terms is always the same, and its called common difference.
The nth term is given by:
In which is the first term and d is the common difference.
The first two terms are -3, 4.
This means that
So
The 21st term is
The 21st term is 137.
It looks a little less than 1/2 or 4/8, so probably 3/8 of the gas is left.
The answer is 5 because 5-2=3. S=5