54 Answers

1. Try to notice the differences in each of the following pair of numbers:
7 to 16: +9
16 to 8: 8
8 to 27: +19
27 to 9: 18

Do you see a pattern here? From 7 to 16, 9 was added; from 16 to 8, 8 was subtracted; from 8 to 27, 19 was added; from 27 to 9, 18 was subtracted.

If this pattern continues, then the sixth number would be 38, which would be 9 + 29. The seventh number would be 10, or 38  28.


I split the sequences into two:
From: 7, 16, 8, 27, 9
to: 7, 8, 9
and: 16, 27, so the next number is 38.