Problema Solution
You ride your bike to campus a distance of 5 miles and return home on the same route. Going to campus, you average 9 mph faster than on your return trip home. If the round trip takes one hour and ten minutes, what is your average rate on the return trip?
Answer provided by our tutors
Let going speed= x mph
So, return speed=x+9 mph
Round trip take 1hour 10 minute= 1.167 hours
So, Average speed on round trip= Total distance/ total time
(x+x+9)/2= (5+5)/(1.167)=8.56
2x+9=2*8.56=17.13
2x=17.13-9=8.13
x=8.13/2=4.065=4(approx)
Average speed on return trip=4+9=13 mph