Answer:
29 adults went to the zoo
158 children went to the zoo
Step-by-step explanation:
Let x represent the number of adults that went to the zoo
Let y represent the number of children that went to the zoo
From the question, we can go ahead and set up the below system of equations;

We'll go ahead and solve the above system of equations simultaneously following the below steps;
Step 1: Express y in terms of x in Equation 1;

Step 2: Substitute y in Equation 2 with (187 - x) and solve for x;

So 29 adults went to the zoo
Step 3: Substitute x in Equation 3 with 29 and solve for y;

So 158 children went to the zoo