Homework Help: Simple Momentum problem

[SOLVED] Simple Momentum problem

A particle initially has a speed of 0.47c.
(a) At what speed does its momentum increase by 1%?
.4747c
(b) At what speed does its momentum increase by 10%?
____c
(c) At what speed does its momentum increase by 100%?
____c

To get the answer for part a, i just multiplied the speed by 1.01. I assumed that I would do the same, except 1.1 and 2 for parts b and c respectively, but the answers are not right. I have a feeling I'm just missing something but can't quite figure out what it is.

 

ahhh right now i see!