Answer:it will take 1 hour before they meet.
Explanation:
The distance between Fred's house and Jon's house is 6 miles. This means that by the time they meet, both of them would have covered a total distance of 6 miles.
Let t represent the time spent by Fred in covering his own distance and also the time spent by Jon in covering his own distance since they left their houses at the same time.
Distance = speed × time
Distance covered by Fred would be
4 × t = 4t
Distance covered by Jon would be
2 × t = 2t
Since total distance = 6 miles, then
4t + 2t = 6
6t = 6
t = 6/6 = 1