Answer:
Let's assume that the number of children who used the public swimming pool is 'x' and the number of adults who used the pool is 'y'.
From the given information, we can form two equations:
x + y = 454 (equation 1) --> the total number of people who used the pool
1.5x + 2.5y = 1043 (equation 2) --> the total revenue collected from admission fees
We can use these equations to solve for 'x' and 'y'. Let's start by multiplying equation 1 by 1.5 to eliminate 'x':
1.5x + 1.5y = 681 (equation 1 multiplied by 1.5)
1.5x + 2.5y = 1043 (equation 2)
Now, we can subtract equation 1 from equation 2 to eliminate 'x' and solve for 'y':
2.5y - 1.5y = 1043 - 681
y = 224
So, there were 224 adults who used the pool. We can substitute this value into equation 1 to solve for 'x':
x + 224 = 454
x = 230
Therefore, there were 230 children who used the pool.