Humpty Dumpty sat on a wall, admiring his new digital watch which displayed hours 15:21
and minutes only. He noticed that it was when Jack and Jill set up the hill, but that
when they later came tumbling down again his watch showed only 10:51. At that point
Humpty realised that he'd had his watch on upside down all the time! How long did Jack
and Jill take to go up the hill and down again?
hours
Dand
minutes