The way I did it in school a long time ago? 450 divided by 100, times 15 (67.5)
An infinite number of numbers can be divided by 450. The smallest two numbers that can be divided by 450 are 450 (450 divided by 450 equals 1) and 900 (900 divided by 450 equals 2).
25
15% of 450 = 15% * 450 = 0.15 * 450 = 67.5
60000
50.7042
450-15%=450*.85=450=382.5
450
450
2.3889
12.5
1, 2, 3, 5, 6, 9, 10, 15, 18, 25, 30, 45, 50, 75, 90, 150, 225, 450.