Question

A red car and a blue car are traveling at the same speed. The red car drives 3 hours. The blue car drives another half hour and goes 25 more miles. Which equation can be solved to find how fast the cars are going? (The boxes are plus signs )

Answer 1

. Distance = Speed * Time

Let s represent the speed of the cars in miles per hour. The problem statement tells you

.. red car distance + 25 miles = blue car distance

.. s*3 + 25 = s*(3 + 0.5)

.. 25 = 0.5s ... subtract 3s from both sides

.. 50 = s ... multiply by 2

The speed of the red and blue cars is 50 miles per hour.

Answer 2

3.5x = 25 + 3x

Explanation:

Let x be the speed in miles per hour of both red car and blue car,

We know that,

Distance = speed × time,

If time taken by red car = 3 hours,

Then the distance travelled by red car = 3x

Now, if the time taken by blue car = 3.5 hours,

Then the distance travelled by blue car = 3.5x

According to the question,

Distance covered by blue car = 25 miles + Distance travelled by red car

3.5x = 25 + 3x

Which is the required equation.