Final answer:
To find the stool number, which is X, we set up the equation 0.40*X - 40 = 40, added 40 to both sides, and then divided by 0.40 to find that X equals 200.
Step-by-step explanation:
The question is asking us to solve for the stool number in a mathematical equation. According to the question, 40 subtracted from 40% of the stool number results in 40. This can be represented by the equation 0.40*X - 40 = 40. To find the stool number, we need to perform some algebraic rearrangements.
First, we need to add 40 to both sides of the equation to isolate the term involving X on one side: 0.40*X = 80. Then, we divide both sides by 0.40 to solve for X, which gives us X = 80 / 0.40, leading to X = 200.
Therefore, the stool number is 200.