<PRE><B>Question 892378</B>
A driver took a day trip driving at two different speeds.
 He drove 60 miles at a slower speed and 160 miles at a speed 10 mph faster.
 If the time spent during the faster speed was twice that spent at a slower speed, find the two speeds during the trip.
:
let s = the slower speed
then
(s+10) = the faster speed
:
Write a time equation, time = dist/speed
:
160 mi time = twice 60 mi time
{{{160/(s+10)}}} = 2*{{{60/s}}}
{{{160/(s+10)}}} = {{{120/s}}}
cross multiply
160s = 120(s+10)
160s = 120s + 1200
160s - 120s = 1200
40s = 1200
s = 1200/40
s = 30 mph is the slow speed
then, obviously;
40 mph is the faster speed
:
:
Check this; find the actual time at each speed
60/30 = 2 hrs
160/40 = 4 hrs

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