21.
0.75 21/28 is the same as 3/4 (seven divides both 21 and 28) and three quarters is 0.75
Reduced to its most simplified form, 21 over 12 (or 7/4) is "one and three-quarters" 13/4
3/4 x 21 = 15.75
It is 21 quarters which is 5 and one quarter which is 5.25 in decimal.
14 quarters plus 7 quarters = 21 quarters= 5 and a quarter (1 quarter is 1 fourth)
28*3/4 = 21
16 over 21
16/21 = 76.2%
28 X .75 = 21 or 28 x 3/4 = 21
14/16, 21/24, 28/32
1/3 + 3/7 = 16/21