Number pattern: find the step (difference) between consecutive terms.

Pattern	=	0.10, 0.15, 0.20, 0.25, ?, ?
Find the difference: 0.15 - 0.10 = 0.05, 0.20 - 0.15 = 0.05. The pattern adds 0.05 each step.
Fourth term	=	0.25 + 0.05 = 0.30
Fifth term	=	0.30 + 0.05 = 0.35