Urgent Bug: mastery challenge

mastery challenge completes and rewards points without solving a certain amount of questions in a row (example: solve 3 in a row is considered a success even when 3 questions are solved incorrectly instead of problems continuing until solving 3 questions -correctly-in a row is achieved)

Still a problem: Needs fixes, videos under exercises are mixed up.only the videos for the first exercise show up

+ we want the U.S. Classes even when we are not in U.S. Please stop the automatic change to NCERT

arrivedercifrog about Khan Academy