To figure this out just multiply 1,5 times the number of months in between the month of august and may. There are 9 months between august and may. The formula for this problem is 1.5 * 9. the answer is 13.5, so itmar grew 13.5 inches. Also you should work on your english, you made some mistakes.
If 20 chairs are sold, revenue is $4,000. At least $9,000 in additional revenue is required. To earn $9,000, a minimum of 15 tables would need to be sold, which is fine since a maximum of 19 tables is permitted to be sold.
