Question

Cars A and B leave the same place and travel in the same direction along a straight road. Car A travels at 60 km/h and car B travels at 72 km/h. After how long will they be at 8km apart​

Answer 1

Answer:

$\frac{2}{3}$ hours

Step-by-step explanation:

Let $t$ be equal to the time that passes for Car A and Car B to be 8 km apart.

Let $A$ be equal to the distance that Car A travels within $t$.

Let $B$ be equal to the distance that Car B travels within $t$.

1) Create equations

$Distance = Time*Velocity$

Therefore:

$A=60t$

$B=72t$

We also know that the distance between the two cars would be 8 km. Therefore:

$B-A=8$

2) Solve for t (the time it takes for Car A and Car B to be 8 km apart)

Plug $A=60t$ and $B=72t$ into $B-A=8$

$72t-60t=8\\12t=8\\t=\frac{8}{12} \\t=\frac{2}{3}$

Because the velocity unit is km/h, we know that t will be in hours. Therefore, Car A and Car B were 8 km apart after $\frac{2}{3}$ hours.

I hope this helps!