To solve this problem what you can do is the following rule of three:
40 iris blooms -----> 100%
x iris blooms -------> 115%
Clearing the value of x we have:
x = (115/100) * (40)
x = 46
Then, comparing with last year we have:
40-46 = 6
Answer:
Savanna had this year 6 more iris blooms than last year.
