Answer:
Joel is moving with 60 mph speed.
Step-by-step explanation:
If Kyle has a speed of u mph and his brother has the speed of v mph, then as they are moving in the opposite direction, their resultant speed will be (u + v) mph.
Now, after traveling for 6 hours, they are 780 miles apart.
So, [tex]u + v = \frac{780}{6} = 130[/tex] ......... (1)
Now, if Kyle drives 10 miles per hour faster than Joel, then
u = v + 10
⇒ u - v = 10  ........ (2)
Now, solving equations (1) and (2) we get,
2u = 130 + 10 = 140
⇒ u = 70 mph
From equation (2) we have, v = u - 10 = 60 mph.
Therefore, Joel is moving with 60 mph speed. (Answer)
