All of these experiments have ended. Deleting all of the alternates except for age_word_problems_alternate which now replaces age_word_problems. Test Plan: none Auditors: eliana
…tly-expanding whitespace problem in the cleaner.
Summary: Add video hints, solution only, and steps only to the existing exercise with detailed hints Test Plan: Tested each locally Reviewers: stephanie Reviewed By: stephanie Differential Revision: http://phabricator.khanacademy.org/D929