Question 24943
First your can simplify 1/4 - 0.25h
Truck's peed = 56mph
Cars' speed = 64mph
After 1/4 hour later with the truck = 56(x+0.25) 
In where x is the distance.
Car's distance = 64x 


56(x+0.25)=64x
56x+14=64x
simplify
8x=14
{{{8x/8=14/8}}}
x=1.75


hence it will take the truck 1.75hour to cross the car
Paul.