Karl wants to lose some weight by burning extra calories each week (2 kg =
approx. 3000 calories). He plans to achieve this by riding a bicycle, which
burns 350 calories an hour, and by walking, which burns 200 calories an
hour. If Karl has 10 hours per week to devote to exercise, determine the
combination of walking and cycling that will allow him to achieve his goal
of burning exactly 3000 calories.
