Complete the series. 9 = 4, 21 = 9, 22 = 9, 24 = 10, 8 = 5, 7 = 5, 99 = 10, 100 = 7, 16 = ?, 17 =? 16=4, 17=10 16=9, 17=5 16=7,17= 9 16=7, 17= 6