Which number is a factor of 21, but not a multiple of 3?

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

Layla answer 21 of the 25 questions on his history test correctly.what decimal represents the fraction of problem he answer incorrectly.

A)a square brown tarp has a square green patch green in the corner the side length of the tarp is (x + 8) and the side length of the patch is x what is the area of the brown part of the tarpb)a square red placemat has a gold square in the corner the side length of the gold square is (x - 2) inches with the width of the red region is 4 in what is the area of the red part of the placemat