Problema Solution
mellissa drove to the mountains last weekend. there was heavy traffic on the way there, and the trip took 8 hours.when Mellissa drove home there was no traffic and it only took 5 hours. if her average rate was 21 miles an hour faster on her trip home how far away from the mountainns does Mellissa live.
Answer provided by our tutors
et
t1 = 8 hr the time of the trip on the way up
t2 = 5 hr the time of the tip on the way down
v1 = the avg. rate on the way up
v2 = the avg. rate on the way down
her average rate was 21 miles per hour faster on the trip home
v2 = v1 + 21
since avg.rate = distance/time => distance = avg.rate*time
the distance of the trip up = the distance of the trip down
t1*v1 = t2*v2
8*v1 = 5*(v1 + 21)
by solving the equation we find
v1 = 35 mph
click here to see the step by step solution of the equation
the distance = v1*t1 = 35*8 = 280 miles
Mellissa lives 280 miles far from the mountains.