Car speeds

A truck left Beroun at 7 o'clock in the direction of Prague on the highway in the fog. In 20 minutes after that, a car drove by at the same place and along the same route at a 27 km/h higher speed. The passenger car overtook the truck after another twenty minutes. What were the speeds of the two cars?

Final Answer:

a =  27 km/h
b =  54 km/h

Step-by-step explanation:


b = a + 27
a · (20+20)/60 = b · 20/60

a-b = -27
40a-20b = 0

Pivot: Row 1 ↔ Row 2
40a-20b = 0
a-b = -27

Row 2 - 1/40 · Row 1 → Row 2
40a-20b = 0
-0.5b = -27


b = -27/-0.5 = 54
a = 0+20b/40 = 0+20 · 54/40 = 27

a = 27
b = 54

Our linear equations calculator calculates it.



Help us improve the example. If you find a mistake, let us know. Thank you!







Tips for related online calculators
Do you have a linear equation or system of equations and are looking for a solution? Or do you have a quadratic equation?
Do you want to convert velocity (speed) units?
Do you want to convert time units like minutes to seconds?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: