The ratio of pink roses to yellow roses in a flower arrangement is 5: 3 if there are 15 yellow roses then how many total flowers are in the arrangement

The final answer is 24 pink roses (1.6 * 15) I got 1.6 from 5/3

Pink roses: 5
yellow roses: 3

If yellow roses:15
pink must be: 25 (because 3 roses x 5 = 15 roses, and multiply by 5 for pink roses 5 x 5=25)

Then, add. 15 yellow roses + 25 pink roses= answer