Question

The distance y (in mi) covered by Car 1 is given by the equation, $y$ = 240$x$. The distance covered by Car 2 is given by the equation, $y$ = 320$x$.
Which one of the following statements is true regarding the speeds of the two cars?

• A. Speed of Car 1 is 80 mi/h more than Car 2.
• B. Speed of Car 2 is 80 mi/h more than Car 1.
• C. Both cars have equal speeds.
• D. Can't be determined

Answer 1

The correct option is B Speed of Car 2 is 80 mi/h more than Car 1.

For Car 1:

Distance covered by Car 1 is given by, $y=240x$

We know,
Speed = $\frac{Distancetraveled}{Timetaken}$

Putting the values, we get,
Speed = $\frac{Distance\left(inmi\right)}{Time\left(inh\right)}=\frac{y}{x}=240$

So, speed of Car 1 is 240 mi/h.

For Car 2:

Distance covered by Car 2 is given by, $y=320x$

Putting the values in the equation representing speed, we get,
Speed = $\frac{Distance\left(inmi\right)}{Time\left(inh\right)}=\frac{y}{x}=320$

So, speed of Car 2 is 320 mi/h.

Now, we know,
$240+80=320$
or, $320-80=240$.

∴ Speed of Car 2 is 80 mi/h more than speed of Car 1.