Ratio equivalent to 1:3
2:6
3:9
4:12
These are all equivilant
1:3Multiply by 2, 3, 4, 5.21: 23 = 2 : 631: 33 = 3 : 941: 43 = 4 : 1251: 53 = 5 : 15Equivalent ratio could be either of 2:6, 3:9, 4:12, 5:15Hope this helps.