You would Multiply 9% and 10.
Keep this in mind whenever you see the word "of" in any kind of math problem like this you would multiply.
So if you multiply 9% and 10 you would get your Grand Total of 0.9
Again keep that in mind it will save you the hassle :)
I think the mean with outliers excluded are called trimmean.
Octagons have 8 sides. If each side is 5 feet then the perimeter is 40 feet. You add up the sides.
Not sure but I think she has 1 31/35 yards of ribbon.