You can't take 11-16 (seconds) so you need to borrow one minute and convert it to seconds; adding the 60 seconds to the 11 seconds making it 71 seconds. Change it to 5 minutes and 71seconds - 3 minutes and 16 seconds; then subtract. 5 minutes - 3 minutes = 2 minutes. 71 seconds - 16 seconds = 55 seconds. The total about left is 2 minutes and 55 seconds.