Answer:
The number of adults is 87, children is twice that amount (174), and the difference (62) is children.
Step-by-step explanation:
Let a be the number of adults. So, 2a is the number of children. 323 - 3a is the number of students.
5(2a) + 7(323 - 3a) + 12a = 2348
10a + 2261 - 21a + 12a = 2348
a = 87
