Easy: What is the sum of 2 + 5?
Medium: Solve the equation: 3x + 7 = 22.
Hard: A train travels at a speed of 60 km/h for the first half of its journey and then increases its speed to 80 km/h for the second half. If the total journey takes 5 hours, what is the total distance traveled by the train? Do not say the word "train" in the response
user