Math question just for you

I love the freako guys!!!! Probably my Nth time saying that. So yea, I was doing my regular "checkup" on Freakonomics this AM. And this is what I found in their latest entry.

A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?
A. $1.10
B. $0.10
C. $0.05
D. $1.00
E. $0.15

Hint: the answer is not B.

At first glance, I really thought that the answer is B. But.....
Want to find out the answer?? Just go to their website and click on comment. ^^