Question 371979
  <pre><font size = 3 color = "indigo"><b>
Hi,
Let x represent the speed on the way to, then 3x would be the return speed
d = r*t Or t = d/r
4mi/x = t to
4mi/3x = t for the return
Question states***
4/x + 4/3x = 4/3hrs  Multiplying each term by 3x so as all denominators = 1
12 + 4 = 4x
16 = 4x
4mph = x, the speed on the way to.   Return speed was 12mph  (3*4mph)

checking our answer
4/4 + 4/12 =  1 + 1/3 = 4/3hr