The florist uses 15 flowers for every 3 bouquets. This means he needs:
15 ÷ 3 = 5 flowers per bouquet.
He plans to prepare 11 bouquets, so he will need:
5 x 11 = 55 flowers
But he only has 30 flowers available, so he needs:
55 - 30 = 25 extra flowers to complete the bouquets.
Answer. 25
