Answer:
42 mph
Step-by-step explanation:
From 2 p.m. to 6 p.m. 4 hours passed, so the truck and the motorcycle were on the road for 4 hours until they met.
Motorcycle in 4 hours at a constant speed of 45 mph travelled
[tex]45\cdot 4=180\ miles[/tex]
The distance between the motorcycle and the truck is 348 miles, so the truck travelled
[tex]348 -180=168\ miles[/tex]
If x mph is truck's speed, then
[tex]168=4\cdot x\\ \\x=\dfrac{168}{4}=42\ mph[/tex]
