You probably don't want to as there is significant overlap between OG 10
and GMAT Prep. Not recommended if you plan on using GMAT Prep.
For OG 10:
1. More questions - 1,400 questions vs. 900 in the OG 11
and OG 12
2. Price - right now it is under $10 with shipping for a used copy
3. Not too much overlap with OG 11
or OG 12
1. Significant overlap with GMATPrep and PowerPrep. Also some overlap with ETS paper tests is reported.
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