numeracy

21, 4, 20, 17, 3, 19, 19, 8, 14 ... and what comes next?

(Answer on Tuesday)

Yesterday's answer:

Start by inverting both hourglasses, then either start the egg when the smaller is finished, giving it another seven minutes after the larger runs out, or put the egg on at the start and invert the larger hourglass when the smaller runs out.