Final answer:
Jane walked a total distance of 36 miles this month, which is 90% of the distance she walked last month. To find the distance she walked last month, divide 36 by 0.90. The answer is 40 miles.
Step-by-step explanation:
To find the distance Jane walked last month, we need to divide the total distance she walked this month by 90% (0.90). Let x represent the distance she walked last month. So we have the equation 0.90x = 36. To solve for x, we divide both sides of the equation by 0.90: x = 36 / 0.90. Using a calculator, we find that x = 40 miles. Therefore, Jane walked 40 miles last month.