In the morning, May Drove to an appointment at 50 mph. Her average speed on the return trip was 40 mph.

Question

The return trip took 1/5 hour longer. How far did she travel to the appointment?

Answer 1

Hey Chris,

 

r₁ = speed to appointment = 50

r₂ = speed home = 40

 

t₁ = time to appointment

t₂ = time home = t₁ + 1/5

 

d₁ = distance to appointment

d₂ = distance home

d₁=d₂

 

So using d=rt  (distance = rate x time)

 

d₁ = r₁t₁

d₁ = 50t₁

 

d₂ = r₂t₂

d₂ = 40(t₁+1/5)

 

Since d₁=d₂

 

50t₁ = 40(t₁+1/5)

50t₁ = 40t₁ + 8

10t₁ = 8

t₁ = .8 hours

 

Now we need to find distance, so we're not done.

 

d₁ = r₁t₁

d₁ = 50(.8)

d₁ = 40 miles