Final answer:
The highest possible price of the skirt is $25.
Step-by-step explanation:
To find the highest possible price of the skirt, let's assume that the price of the skirt is represented by 'x'. According to the given information, the price of the jacket is $20 more than 3 times the price of the skirt, which can be written as 3x + 20. Mrs. Scott decided to spend no more than $120, so we can set up the following inequality: 3x + 20 + x ≤ 120. Simplifying this inequality, we have 4x + 20 ≤ 120. Subtracting 20 from both sides, we have 4x ≤ 100. Finally, dividing both sides by 4, we find x ≤ 25. Therefore, the highest possible price of the skirt is $25.