A high-speed train makes a 360 mile nonstop run between two major cities in 712 hours. The train travels 80 mph in the country, but safety regulations require that it travel only 20 mph when passing through smaller, intermediate cities. How many hours are spent traveling through the smaller cities?

3 answers

712 hrs ??? , that would be a whole month !

I will assume you meant 7 1/2 hrs or 7.5 hrs

let the distance in the country be x miles
then the distance through towns is 360-x miles

x/80 + (360-x)/20 = 7.5
multiply by 80 , the LCD
x + 4(360-x) = 600
x + 1440 - 4x = 600
-3x = -840
x = 280

so 280 miles through country and 80 miles through towns
time in towns = 80/20= 4 hrs
Thanks you helped me !!
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