I had a look at the other free tests, the economist,
kaplan and I feel like they are equally deficient. Manhattan was ok, but it had too much emphasis on vocabulary, which was not the case with the ETS tests.
Compared to the GMAT there seems to be a lot of scarcity when it comes to adequate CATs. And GRE is supposed to be the more popular one... how do you explain this?
Your tests could be useful for people unfamiliar with the GRE math. However, the fact that there is a question which requires the use of sin/cos is a major red flag, that the other questions might also not reflect the requiered exam curriculum.
I would suggest you make the tests free and use them as a tool for making the forum more popular as well as polishing the questions and removing the errors. In their current state I wouldn’t pay the price you are asking. Quality is more important than quantity.
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