How long will it take to catch up?

Question

Julio leaves for school at 8:05 am and the bus travels at a rate of 30 mph. Julio's mom discovers that Julio left his lunch at home. How long will it take Julio's mom to catch the bus if she leaves at 8:10 am going at 40 mph?

Answer 1

Julio is travelling 5 min or 1/12 hour more than his mom.

 

30(t + 1/12) = 40(t)           distribute

30t + 2.5 = 40t                  subtract 30t from both sides

2.5 = 10t                            divide both sides by 10

0.25 = t

 

Julio's mom catches up to him after one-quarter of an hours (15 minutes).