# Ratios as fractions in simplest form

## Video transcript

Write 15:25 as a fraction in simplest form. So 15 to 25 is just a ratio, and we can write it. So they've given us 15 to 25. And you can write this ratio as a fraction, as 15 over 25. And if we want to put this in simplest form, we just have to think about what is the largest number that divides into both 15 and 25? Or what is their greatest common factor? When you just eyeball it, you say, well, 5 goes into both of them, and I'm pretty sure that's the largest number that divides into both, so let's divide both by 5. If there is a larger number, then we might be able to see it once we've simplified it a little bit more. So let's divide the numerator and the denominator by 5 and see what we get. So now we get 15 divided by 5 is equal to 3. And 25 divided by 5 is equal to 5, and now we have 3/5. 3 and 5 don't share any common factors greater than 1, so it is in simplest form. So we've done what they asked. We've written it as a fraction in simplest form. We could also write this, if we want to write it in this type of notation, as 3:5.