I went through those subject tests as well, and heres what I think. Some of them are really easy to get through, and some are insane. Thats because some of the tests are all non-word problems (easy=fast), and other tests are ALL word problems(hard=long=impossible to finish). I haven't taken the DAT, but from what I have heard, there is NO WAY all the questions are word problems. I would say a MAX of 15. The subject tests have 25/25!!! So I would just try to do the word problem ones to get good at them, and be able to do 25 word problems in 40 Mins. Basically if you spend 1.5 mins on word problems, and 1 min on non-word problems(long time) on a DAT with 15 word/25 non-word, it would take 47.5 minutes to finish. Time is a huge issue, but non-word problems really shouldn't take more than 30-45seconds. So just make sure you realize that those subject tests are a little off the mark. It took me 40, and 45 minutes to do the two ALL word problem sets, and 15, 15, 20 to do three of the non-word problem sets, just to compare.
But good luck with your studies, my test is in less than two days
