Credit card question...interest rates

What does this mean? It's a screencap from my AMEX online statement. I never carry a balance, but I'm trying to figure out which interest rate is the 'real' one, and I am confused:

amex.JPG

 

[aolj]

I think they will charge you both.

Might be wrong.

 

[ObiDon]

Maybe the lower rate is for purchases and the higher rate is for cash advances?

 

[Nyical]

One is for credit the other is for cash adv they tend to have a higher interest rate.

 

Originally posted by: ObiDon
Maybe the lower rate is for purchases and the higher rate is for cash advances?

Hmmm...that sounds right - AMEX gave me a pretty high limit for a student card, so I can't imagine that they'd gouge me to the tune of 31% if I were to carry a balance. I'll email them and ask though.