Ratios and fractions are interchangeable (for the most part). A fraction is a type of ratio. And we've all worked with fractions before, so that's what we'll do here.
I can say that the ratio 3:1 is the same as the fraction 3 / 1. Using that fraction, it is fairly easy to find equivalent fractions.
3 / 1 = 6 / 2 = 9 / 3 = 30 / 10
...And so on
Another example, 5:6 = 5 / 6.
5 / 6 = 10 / 12 = 15 / 18 = 30 / 36
To find equivalent fractions, all you need to do is multiply both the numerator and denominator by the same number. As long as that number is the same (and your multiplication is correct), then the new fraction will be equivalent to the original.
Hope this helps!