111
111
21, 22, 23, 24
21% of 90= 21% * 90= 0.21 * 90= 18.9
4*90 = 360
21% of 90= 21% * 90= 0.21 * 90= 18.9
90% of 21= 90% * 21= 0.9 * 21= 18.9
111
90 + 21 = 111
Factor 90 and find a combination that would add up to 21. 3x3x5x2. Try 3x3 plus 5x2. Nope. Try 3x5 plus 3x2. 15 + 6 = 21. Got it!
-111
90% of 21 = 18.9So, in order to score 90% on a test with 21 questions,you can't miss more than two of them.
The Greatest Common Factor (GCF) of 21 and 90 is 3.