Question

If the following sequence is geometric, what is the common ratio?

12, 22, 32, 42,...

Answer 1

In a geometric sequence, the ratio between any two consecutive terms is always the same - e.g. 3, 9, 27, 81 is a geometric sequence because we multiply by 3 each time to get the next term. So the common ratio in this sequence is 3.

In an arithmetic sequence, the difference between any two consecutive terms is always the same - e.g. 5, 10, 15, 20, 25, 30 is an arithmetic sequence because we add 5 each time to get to the next term. So the common difference in this sequence is 5.

You should be able to use these definitions to answer your question.

Answer 2

As asnaseer states, you should be able to use the definitions. Before you look for the ratio, though, determine whether the sequence is geometric or not.

Answer 3

thank you to both! that helped alot!