Answer:152 children and 104 adults swam.
Explanation:
Let x represent the number of children tickets. It also means that x children swam.
Let y represent the number of adult tickets. It also means that y adults swam.
On a certain hot summers, 256 people used the public swimming pool. This means that
x + y = 256
The daily prices are $1.75 for children and $2.75 for adults. The receipts for admission totaled to $551.50. This means that
1.75x + 2.75y = 551.5- - - - - -- - - - - -1
Substituting x = 256 - y into equation 1, it becomes
1.75(256 - y) + 2.75y = 551.5
448 - 1.75y + 2.75y = 551.5
- 1.75y + 2.75y = 551.5 - 448
y = 103.5
Approximately 104 adults
x = 256 - y = 256 - 104
x = 152