Khan/khan-exercises — pull request #4039 by kohpangwei (2011-10-09 00:59:57+00:00)
Title: Fix for issue #4029

Floating-point rounding error in rate_problems_2.html (problem collective-action-calculate), due to intermediate variables used to compute the final answer. Fixed by removing intermediate variables and computing the final answer directly.

Problem collective-action-same had the same bug; fixed it by setting TIME_FINAL = TIME_INIT since this is always true.