There are 3 factor pairs of 28. 28 = 1 x 28 28 = 2 x 14 28 = 4 x 7
The factor pairs of 28 are :28,114,27,4
The factor pairs of 28 are 1*28, 2*14, and 4*7
28 has three factor pairs which are:28 = 1 x 2828 = 2 x 1428 = 4 x 7
The factor pairs of 56 are: 1, 56; 2, 28; 4, 14; 7, 8 Therefore, if you exclude itself and 1, there are three factor pairs, but if you include itself and 1, there are four factor pairs.
Factor pairs of 84 are: 2 x 42, 3 x 28, 4 x 21, 6 x 84, 7 x 12
28,114,27,4
20 has 3 factor pairs. Pairs are (1,20), (2,10) and (9,9)
1 & 28, 2 & 14, 4 & 7
1,282,144,7-1,-28-2,-14-4,-7
1, 28 2, 14 4, 7
12 has 3 factor pairs and the pairs are (1,12), (2,6) and (3,4).