siavosh

well I think they gradually get harder, i.e. 3 is harder than one (volume 1) and then obviously volume 2 is harder again.
I'd do exam 3 from volume 1, but if you have time definately try some from volume 2 - but depends what scores you're getting. If you get 75+ on CFAI mock, go straight to volume 2 to really test yourself. But if you're getting 60-70, try exam 3.