OG 12 or OG 11

[atomy1985]

Hi,
I have OG 12. should i go for OG 10 and OG 11 as well?
regards..

[esledge]

If you have OG 12, there's little to be gained by purchasing OG 11. About 600 of the 800 problems in the 11th edition made it into the 12th edition. If 200 different questions justify the cost of the 11th edition for you, then go for it.

I would not recommend buying the 10th edition. Not only is there a lot of overlap between 10th/11th and even the 10th/12th, but the problems in the 10th edition are not ordered by difficulty and the explanations are not nearly as clear as those in the 11th and 12th editions.

[vicksikand]

Not only is there a lot of overlap between 10th/11th and even the 10th/12th, but the problems in the 10th edition are not ordered by difficulty and the explanations are not nearly as clear as those in the 11th and 12th editions.

Is this construction parallel? I thought the correct form was "not only X, but also Y".
Overlap "between X and Y" is correct - I cant say the same about the other set.
I dont want to come across as rude - it's just that I have started analyzing every sentence I read.

[Ben Ku]

Not only is there a lot of overlap between 10th/11th and even the 10th/12th, but the problems in the 10th edition are not ordered by difficulty and the explanations are not nearly as clear as those in the 11th and 12th editions.

Is this construction parallel? I thought the correct form was "not only X, but also Y".
Overlap "between X and Y" is correct - I cant say the same about the other set.
I dont want to come across as rude - it's just that I have star

Good eye! This shows that what's typically acceptable in common speech may be wrong on the GMAT. Just a note about this idiom: although "not only X, but also Y" is the preferred idiom on the GMAT, "not only X but Y" has been seen in correct answers. We would classify this construction as being "suspect."

Hope that helps.