The speed of car is 55 miles per hour and speed of truck is 50 miles per hour .
Step-by-step explanation:
Let the speed of the car is v miles/h , therefore the speed of truck is ( v - 5 ) miles per hour .
Because time = 

Thus in case of truck the time t₁ = 

In case of car the time t₂ = 

But time is the same in both cases , therefore 
 =
 = 

or 30 v = 1650 
or v = 55 miles per hour 
Therefore speed of car is 55 miles per hour 
Thus speed of truck is 50 miles per hour