SOLUTION: Mary and John have both completed a trip up an escalator. John took 15 steps on the way up and took 12 seconds to reach the top. Mary took only 7 steps, and took 18 seconds to reac
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Question 1149393: Mary and John have both completed a trip up an escalator. John took 15 steps on the way up and took 12 seconds to reach the top. Mary took only 7 steps, and took 18 seconds to reach the top. How many steps does the escalator have in total? Answer by greenestamps(13200) (Show Source):
Since John took 15 steps while on the escalator, the number of steps the escalator moved during his time on it was x-15; since Mary took 7 steps while on the escalator, the number of steps the escalator moved during her time on it was x-7.
Since the escalator moves at a constant rate, the ratio of the numbers of steps the escalator moved during their trips is the same as the ratio of times spent on the escalator. So
