Question

Daniel and Stanley leave Stanley's house at the same time. Daniel drives north and Stanley drives west. Daniel's average speed is 11 mph slower than Stanley's. At the end of one hour, they are 45 miles apart. Find Stanley's average speed. (Round your answer to the nearest tenth.)

Answer 1

Answer: Stanley's average speed is 28 mph.

Step-by-step explanation:

Let x represent Stanley's average speed.

Daniel's average speed is 11 mph slower than Stanley's. This means that Daniel's average speed is

(x - 11) mph.

Distance = speed × time

At the end of one hour, they are 45 miles apart. Distance covered by Stanley after 1 hour would be

x × 1 = x miles

Distance covered by Daniel after 1 hour would be

1 × (x - 11) = (x - 11) miles.

Since the total distance covered is 45 miles, then

x + x - 11 = 45

2x = 45 + 11

2x = 56

x = 56/2

x = 28 mph