Two? ferries leave at the same time from a city to go to the same island.

Question

The first? ferry, travels at 33 miles per hour. The second? ferry, travels at 27 miles per hour. In how many hours will the two ferries be 18 miles? apart?

Answer 1

Hello Louisa

 

This is a distance rate time problem.  We want to determine the distance between two ferries.

 

For the first ferry

d₁ = distance the first ferry travels

t₁ = time the first ferry travels

r₁ = speed the first ferry travels = 33mph

d₁ = 33t₁

 

For the second ferry
d₂= distance the second ferry travels
t₂ = time the second ferry travels
r₂ = speed the second ferry travels = 27mph

d₂ = 27t₂

 

The total distance travelled, d₁ + d₂ = 18

and t₁ = t₂, so let's just call it t 

33t₁ + 27t₂ = 18

33t + 27t = 18

60t = 18

t = .3

 

So it will take .3 hours (18 minutes) for the two ferries to be 18 miles apart.