Question

Jim and Ralph leave the intersection of Lacey and Lilac at the same time, but bicycling in opposite directions. After 45 minutes, they are 24 miles apart. If Jim pedals 4mph faster than Ralph, find the cycling speed for each.​

Answer 1

Let x = Ralph's speed. Jim's speed is x + 4. In 45 minutes, Jim travels 45 * (x + 4) = 45x + 180 miles. In 45 minutes, Ralph travels 45 * x = 45x miles. Jim and Ralph are 24 miles apart, so 45x + 180 = 45x + 24. 180 = 24. x = 6 mph. Ralph's speed is 6 mph. Jim's speed is 6 + 4 = 10 mph.