<PRE><B>Question 618505</B>
A tourist can bicycle 33 miles in the same time as he can walk 12 miles. If he can ride 7 mph faster than he can walk, how much time should he allow to walk a 30-mile trail?

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Let x be the speed that he walks

since he can bicycle 33 miles AS SAME TIME as he walks 12 miles.

we have the equation for time:

33/(x + 7) = 12/x
33x = 12(x + 7)
33x = 12x + 84
33x - 12x = 84
21x = 84 
x = 4 mph

If the trail is 30 miles then the time he must walk is:

t = distance / speed = 30/4 = 7.5 hours or 7 hours and 30 minutes.

Hope it helps you:)

John10</PRE>