Question 45291
8/28 Is a fractional representation because 4 times 2 is 8 and 4 times 7 is 28.  4/14 Is a representation because 2 times 2 is 4 and 2 times 7 is 14.  6/21 Is a representation because 3 times 2 is 6 and 3 times 7 is 21.  The only one that's NOT a representation is 4/21, because while 2 times 2 is 4, 2 times 7 is 14, NOT 21.