Easy answer: very much so!

Longer answer: yes, as long as you aren't scoring really high in math - say, over about 80th percentile. There are a handful of pretty tough math problems in the OG, but most of them are medium to medium-hard level problems. This is excellent if you're not a math whiz, but if once you get your math raw score into the upper 40s you will probably need to reference another book.

Hope this helps!

Thanks VP_Jim)
And what about verbal section?
What sort of book could you advise for studying more difficult types of math questions?