In order to clear out the confusion at last MITx posted the sample review problem and the exam pattern under course info section. Students have only 3 chance to check their answer either right or wrong. With a wrong answer in the third attempt you will be shocked !!
They says that the review problem contains only the sample problem, does not indicates the number of given question the exam or the others. what do you think to continue the same performance or better ??
Again Midterm contain 30% of total grade, HW is 30% and the finale have 40% so, got under 60% marks in midterm cause you to downgrade of your total grade to 60% (or fail !). You have only 24 hours to complete your exam.
So, be prepared for the exam 🙂