Question

What's the common difference in 2,10,50?

Answer 1

Subtract adjacent terms:

10-2 = 8

50-10 = 40

The results are not the same, so we do not have a common difference.

But we do have a common ratio because dividing adjacent terms gets us the following

10/2 = 5

50/10 = 5

The common ratio is 5. It means we multiply each term by 5 to get the next term. The sequence is geometric.

The nth term formula is
`a_n = 2*5^(n-1), \ \text{ where n = 1, 2, 3,}\ldots`