Question 519766
d = r*t is the basic distance equation
.
When the car overtakes the truck, they will have traveled the same distance.
But the car will have been traveling for 1 fewer hour.
.
Truck:
d = 45*t
.
Car:
d = 60*(t-1)
.
d=d
.
45t = 60(t-1)
.
45t = 60t -60
-15t = -60
t = 4
.
Answer:  In 4 hr the car will overtake the truck.
.
Check the distances each travels.
4*45 = 180
3*60 = 180
.
Done.