We can say that because 3 times 9, which would equal 27, could be the same as 4*9, which would be 36. So Pat needs 36 pints of green paint. Down below is a tape diagram so you can see what it is.
The volume of the shaded region is 1650 cubic feet.
The interest earned by $318 investment is 9/100 x 318= $28.62