What Is The Speed Of The Truck And Car?

Question

A car travels 250km in same time that a truck travels 225km. If the speed of the car is 8km per hour faster than the speed the truck, find both speeds.

Answer 1

Dear Zarayia,

     This problem will need the following equation:  D=r*t, Distance traveled = rate (speed)* time.

 

Here are some notes that you should take:

 

car__________________________250Km    r=rate  r+8 km/hour  The car is faster than the truck.

 

truck_____________________225Km                      r=truck's rate

 

The time is the same for both.  Let time=t

Then just set up a little table with your data:

                    rate    *    time         =   d

Car           r+8/h             t                (r+8)t= 250

 

truck             r                t                  rt=225

 

Now you have a system of equations:              rt+8t=250

                                                                       rt=225              t=225/r 

 

Substitute the amount of one variable into the other equation, r(225/r)+8(225/r)=250. 

 

                                                                    225 +1800/r   =250    Multiply every term on both sides of equation by "r" to get rid of "r" in the denominator.

 

Then collect terms, and solve for "r."   Look at your table, and you should be able to tell how fast each is going.

 

If I helped you, please give me a thumbs up.

                                                               Susan C.