He scored 700.
We figured that if he had skipped the questions he didn't know instead of answering and getting them wrong, he would have scored a 720 or 730. (C. remembers 730; I recall 720.)
That's an important difference because 30-points can be make-or-break in college admissions.
Speaking of which, various metanalyses of SAT coaching put the gain from test prep in the vicinity of 30 points:
Does test preparation help improve student performance on the SAT and ACT? For students that have taken the test before and would like to boost their scores, coaching seems to help, but by a rather small amount. After controlling for group differences, the average coaching boost on the math section of the SAT is 14 to 15 points. The boost is smaller on the verbal section of the test, just 6 to 8 points. The combined effect of coaching on the SAT for the NELS sample is about 20 points.Is this a wisdom of the crowd moment?
The Effect of Admissions Test Preparation: Evidence from NELS:88 (pdf file)
May 1, 2007
I've always assumed parents were being more-or-less ripped-off by the test prep companies. But if 30 points matter to colleges, and test prep companies raise scores by 30 points -- and those 30 points matter most to selective colleges -- then parents are right.
The Official SAT Study Guide, 2nd edition