Math tasks ordered by difficulty level

[BlackHawk]

Hello everybody

For a research project (study) I'm searching math tasks ordered by difficulty (easy to hard) and average time needed to solve. I think and I hope that there is also some ordering according to difficulty level in the GRE tests. I would prefer if the difficulty level is inferred from the analysis of the performance of participants instead of the estimation of a single person (but latter would also be acceptable).

Does somebody know a resource which provides such an ordering of difficulty level and perhaps also the average time to solve for the tasks?

[Corey]

PowerScore has done something similar. They made an overlaid plot of the distributions for percentage of test takers who answered a quant question correctly and which category that question was in. Here's the plot:


I think the big takeaways from this graph are that data analysis questions tend to trip people up more than the average quant question, and that there appear to be some fairly easy arithmetic questions in the quant section that most people get correct.