Answer: 275 adult tickets and 500 children's tickets were sold.
Explanation:
Let a represent the number of adult tickets that were sold.
Let c represent the number of children's tickets that were sold.
The total number of tickets that were sold is 775. It means that
a + c = 775
If adults tickets sold for 2.50 and children’s tickets sold for 1.00 and the total amount was $1187.5, it means that
2.5a + c = 1187.5- - - - - - - - - - -1
substituting a = 775 - c into equation 1, it becomes
2.5(775 - c) + c = 1187.5
1937.5 - 2.5c + c = 1187.5
- 2.5c + c = 1187.5 - 1937.5
- 1.5c = - 750
c = - 750/ - 1.5
c = 500
Substituting c = 500 into a = 775 - c, it becomes
a = 775 - 500
a = 275