Question

Prince Ivan rides Grey Wolf at a constant speed from King's Castle to the Magic Apple Garden in 5 hours. On their return trip to King's Castle, Grey Wolf runs at that original constant speed for the first 36 km. Then he runs the rest of the way 3 km/h faster. What was Grey Wolf's original speed if the return trip took 15 minutes less than the trip from King's Castle to the Magic Apple Garden?

Answer 1

9 and 48 km/hr

Explanation:

The Formula
`S=(D)/(T)` along with its variations are used

Let's say for the initial ride, the speed was x. Because the time was 5 hours, the distance was 5x km. Now for the return. For the first part, the speed remains x but our distance is 36km. So, our time is 36/x hours. For the second part, the speed is x+3 but our distance is 5x-36 (The total minus the distance of the first part.) So, our time is
`(5x-36)/(x+3)`. Now we have the equation
`(36)/(x) + (5x-36)/(x+3)=5-(1)/(4)` as our times add up to 5 hours minus 1/4 of and hour. Solving, we get x=9, x=48.

Answer 2

48 and 9

Explanation:

36/x + 5x-36/x+3 = 5-0.25