(1 & 2/3) ft = (1 ft) + (2/3 ft)
(1 & 2/3) ft = 12 inches + 12*(2/3) inches
(1 & 2/3) ft = 12 inches + 8 inches
(1 & 2/3) ft = 20 inches
If the tree grows 5 inches per year, then it will take 4 years to get to 20 inches since 5*4 = 20. You can also divide to get 20/5 = 4.
So it takes 4 years for the tree to grow 1&2/3 feet tall.
The answer is 891. 99 is the greatest 2 digit number and 9 is the greatest 1 digit number. So the product of the two (multiply them) gives you your answer of 891 (99 x 9 = 891).
I believe the answer is 9, because 1/3 is .33 so 33%. so 33% is equal to 3 buttons and add another 66% which would be another 6 buttons would add up to 99% in all. after that I don't think they would add a quarter of a button.
Look at picture for details