Since 600 is divisible by 4, 600 plus any two digit number "ab",
producing "6ab", will be divisible by 4 if and only if "ab" is
divisible by 4. So the problem amounts only to finding all
two-digit numbers divisible by 4.
The smallest two-digit number "ab" divisible by 4 is 12,
and of course 612 is also divisible by 4.
The largest two-digit number "ab" divisible by 4 is 96,
and of course 696 is also divisible by 4.
12 is 4x3 and 96 is 4x24, and from 3 to 24, inclusive, there are 22
integers. So there are 22. Here are all 22:
"ab" "6ab"
--------------------------
1. 12 because 612 = 4x153
2. 16 because 616 = 4x154
3. 20 because 620 = 4x155
4. 24 because 624 = 4x156
5. 28 because 628 = 4x157
6. 32 because 632 = 4x158
7. 36 because 636 = 4x159
8. 40 because 640 = 4x160
9. 44 because 644 = 4x161
10. 48 because 648 = 4x162
11. 52 because 652 = 4x163
12. 56 because 656 = 4x164
13. 60 because 660 = 4x165
14. 64 because 664 = 4x166
15. 68 because 668 = 4x167
16. 72 because 672 = 4x168
17. 76 because 676 = 4x169
18. 80 because 680 = 4x170
19. 84 because 684 = 4x171
20. 88 because 688 = 4x172
21. 92 because 692 = 4x173
22. 96 because 696 = 4x174
Edwin
