[SmileyEH]

You just start a stop watch. You have until it hits 1:00 to do 1 pullup, then until 2:00 to do 2 more, then until 3:00 3 more etc. So in the 10th minute you have to do 10 pullups in that minute. I was able to finish the 12th minute's pullups so I did 12 + 11 + 10 etc = 78 total.