10:1 = 1000:100 (÷100)
1:17 = 20:340 (÷20)
5:3 = 55:33 (÷11)
21:11 = 63:33 (÷3)
6:7 = 24:28 (÷4)
15:11 = 75:55 (÷5)
To reduce ratios, you must find the greatest common factor that goes in both numbers. You then divide those numbers by the factor and bam! You got your reduced ratio.
