Question 831042
t=d/r

time going = 45/r

time return =45/(3r/4)

Time going + time return = 7/4 hours

{{{45/r + (45/(3r/4))=7/4}}}


{{{45/r + (60/r)=7/4}}}



{{{(60+45)/r=7/4)}}}

105/r =7/4

r= 4*105/7


r=60

speed while going = 60 mph

returning speed = 3/4 *60 = 45 mph