please make answer very clear

A woman has an exercise regimen that includes running, biking, and walking. She has no more than 18 hours per week to devote to exercise, including at most 3 hours of running. She wants to walk at least twice as many hours as she bikes. A woman of her weight will burn on average 525 calories per hour running, 350 calories per hour walking, and 468 calories per hour biking. How many hours per wook should this woman spend on each exercise to maximize the number of calories she burns? What is the maximum number of calories she will burn? The woman should spend hours walking hours running, and hours biking for a maximum calorie expenditure of (Type integers or decimals rounded to two decimal places as needed.)