Answer: 217 children and 264 adults swam in the pool that day.
Step-by-step explanation:
Let x represent the number of children that used the public swimming pool that day.
Let y represent the number of adults that used the public swimming pool that day.
On a certain hot summer day,481 people used the public swimming pool. This means that
x + y = 481
The daily prices are 1.25 for children and 2.25 for adults. The receipts for admission totaled 865.25. This means that
1.25x + 2.25y = 865.25 - - - - - - - - -1
Substituting x = 481 - y into equation 1, it becomes
1.25(481 - y) + 2.25y = 865.25
601.25 - 1.25y + 2.25y = 865.25
- 1.25y + 2.25y = 865.25 - 601.25
y = 264
x = 481 - y = 481 - 264
x = 217
