2 hr 15 min = 2 [tex] \frac{1}{4} [/tex] hours = 2.25 hours
"how far" means distance ... so distance = rate x time
distance = 56 x 2.25 = 126 miles
"how long" means time ... so using the same formula
168 = 56 x time
divide both sides of the equation by 56 to solve
3 hours = time