Answer:
The number of children are 54, number of students are 84 and number of adults are 27.
Explanation:
Let the number of children be

Let the number of students be

Let the number of adults be

As per question,

Now, adults are half of the children.
So,

Now, plug in
in the first two equations.

Multiply equation (3) by -7 and add it to equation (4).
Solve for the remaining variables.


Therefore, the number of children are 54, number of students are 84 and number of adults are 27.