Answer:
1.042% of the total tickets sold 1 child ticket.
Explanation:
As given, 
A Water park sold 72 child tickets and 24 adult tickets.
So, 
The total number of ticket sold by a Water park = Total child ticket sold + Total adult ticket sold
⇒The total number of ticket sold by a Water park = 72 + 24 = 96
Now,
The total child ticket sold = 
 ×100% = 0.75×100% = 75%
×100% = 0.75×100% = 75%
Now, we get
72 child ticket sold % = 75
⇒ 1 child ticket sold % = 
 = 1.042%
 = 1.042%
So, we get
1.042% of the total tickets sold 1 child ticket.