Answer:
40%
Explanation:
At the beach, 45% of people have red towels and 15% have blue towels. If the rest have white, 40% of the people at the beach have white towels.
In order to find the answer, you have to do the following steps:
45% + 15% = 60%
100% - 60% = 40%
Therefore, the answer is 40%.