Question 845919
A motorist drove 150 miles on the highway before driving 50 miles on the mountain roads.
the rate speed on the highway was 3 times the rate on the mountain roads.the time spent travelling the 200 miles was 5 hours.
let s = his speed on the mountain road
then
3s = speed on the highway
:
Write a time equation; time = dist/speed
hywy time + mtn time = 5 hrs
{{{150/(3s)}}} + {{{50/s}}} = 5
reduce the 1st fraction
{{{50/s}}} + {{{50/s}}} = 5
{{{100/s}}} = 5
5s = 100
s = 100/5
s = 20 mph, speed on the mt road
:
find the rate of the motorist on the highway?
3 * 20 = 60 mph on the highway
:
:
Check this by finding the time at each speed
150/60 = 2.5 hrs
 50/20 = 2.5 hrs
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total time: 5 hrs