Question

My teacher just gave me the sequence 7, 13, 19. He told us that the next answer is not 25. Please help.

Answer 1

7, 13 , 19.

An arithmetic sequence is one that has a common difference.

13 - 7 = 6.
19 - 13 = 6.

So the next in the sequence is 19 + 6 = 25.

The next in the sequence is 25. 

It is not affected by what any one says.