Answer:
288 miles
Explanation:
Time taken with traffic = 9 hours
Time taken without traffic = 4 hours
Speed with traffic = x mph
Speed without traffic = x+40 mph
Distance = Speed × time
Distance travelled in 9 hours
9x
Distance travelled in 4 hours
4(x+40)
Since both the distances are same
[tex]9x-4(x+40)=0\\\Rightarrow 9x-4x-160=0\\\Rightarrow 5x-160=0\\\Rightarrow x=\frac{160}{5}\\\Rightarrow x=32\ mph[/tex]
Speed with traffic = 32 mph
Distance travelled = 9×32 = 288 miles
∴ Shen lives 288 miles from the mountains