Problema Solution
A man has to go 10km to catch a bus. He walks part of the way at 7km/h and runs the rest of the way at 12km/h. If he takes 1hr 15minutes to complete the journey, find how far he walks.
Answer provided by our tutors
t + s = 1.25 hrs
and
7t + 12s = 10
== > 7(1.25 -s) + 12s = 10
==> 8.75 - 7s + 12s = 10
==> 5s = 1.25
== > s = 0.25 hr
==> hence, he walks 7 km and runs 3 kms.