Answer:
46%
Step-by-step explanation:
You want to know the percentage of people on the boardwalk if 17% and 37% of the people at the beach are in the water or on the sand, respectively.
If we assume that 100% of the people at the beach will be in one of the three named places, the percentage on the boardwalk will be ...
100% -17% -37% = 46%
46% of people are on the boardwalk.