Question 640682

Mr. Thomas drove his old truck to the city at a rate of 40 mi/hr and drove back home on the interstate at a rate of 60 mi/hr. The total trip took 6 hr. How far is Mr. Thomas's home from the city.

I've tried {{{ 40t +60(6-t)=6}}} and got {{{ 17.7}}}. I checked it and the answer was wrong. I'm not sure what to do.


It appears as though you wanted to do a distance equation, hence 40t + 60(……


It should’ve been: 40t = 60(6 – t). This would’ve given you a time of 3.6 hours. You’d then need to multiply that 3.6 hours by 40 to get a distance of 144 miles, OR

You could also multiply 60 by 2.4 (6 – 3.6) hours to get 144 miles
 

Let distance of his home from the city be D
Time equation: Time taken to travel to city, plus time taken to travel back home, equals total time, OR
{{{D/40 + D/60 = 6}}}
{{{3D + 2D = 720}}} ----- Multiplying by LCD, 120
{{{5D = 720}}}


D, or distance of his home from the city = {{{720/5}}}, or {{{highlight_green(144)}}} miles


You can do the check, I’m sure!!


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