Final answer:
To finish the flower arrangement, Diva needs 8 other flowers.
Step-by-step explanation:
To calculate how many other flowers Diva needs to finish the arrangement, we need to know the total number of flowers she wants in the arrangement. Let's say she wants a total of 20 flowers in the arrangement. If she already has 12 roses, then she needs to find the difference between the total and the number of roses she has. The calculation would be: 20 (total flowers) - 12 (roses she already has) = 8. So, Diva needs 8 other flowers to finish the arrangement.