Question

Carla left the bookstore traveling 12 mph. Then, 3 hours later, Zari left traveling the same direction at 18 mph. How long does Zari have to travel before catching up with Carla

Answer 1

6 hours.

Explanation:

Speed = distance / time.

Carla travels 3 * 12 = 36 miles before Zari leaves the shop.

So Zari travels x miles in the same time as Carla travels x- 36 miles.

So 18 = x/t and 12 = (x - 36)/t

From first equation x = 18t so we have the equation

12 = (18t - 36/t

18t - 36 = 12t

6t = 36

t = 6 hours.