Distance Formula

Question

A boater can travel from Port Clinton to Smithson in 3 hours. If he goes 5 miles per hour faster, he can travel the same distance in 45 minutes less. How far is it from Port Clinton to Smithson?

Answer 1

d=rt

distance = rate of speed times time

d=3r = (3-3/4)(r+5)

3r = (9/4)(r+5)

3r = 9r/4 + 45/4

3r-9r/4 = 45/4

3r/4 = 45/4

3r = 45

r = 45/3 = 15mph

d =3r = 3(15) = 45 miles from Port Clinton to Smithson

if he goes 5mph faster, he's going 20mph

20mph x (3-3/4) of an hour = 20 x 9/4 = 45 miles