Final answer:
There are 48 children and 96 adults in line.
Step-by-step explanation:
To find how many children and adults are in line, we can use algebraic equations and solve for each variable. Let's assume the number of children in line is x. Since there are twice as many adults as children, the number of adults in line would be 2x. According to the given information, the total number of people in line is 144. Therefore, we can set up the equation x + 2x = 144. Simplifying the equation, we get 3x = 144. Dividing both sides by 3, we find x = 48. So, there are 48 children and 2 * 48 = 96 adults in line.