All you have to do is to reduce 4:10 to its lowest form: 2:5. Other examples of the same ratio can be found by multiplying each number in the ratio by a particular number represented by n: 2n:5n. For example, let's put n=3: the ratio becomes 6:15. Put n=4 and we get 8:20; put n=2 and we get 4:10 (that's where we started); put n=10 and we get: 20:50.