To divide by a fraction, simply multiply by its reciprocal.
So 3/5 divided by 3/15 is the same as 3/5 multiplied by 15/3.
To multiply the fractions, just multiple the numerators together and multiply the denominators together.
3/5 * 15/3 = 45/15
Simply the fraction by dividing top and bottom by 15 giving
3/1
and 3/1 is equal to 3
