First we find out how long it would take Mr. Harris to walk to your destination, which we find by multiplying his 2 hour walk by 3 since your destination is 3 times further away, meaning it would take him 2*3= <<2*3=6>>6 hours.
Since you walk twice as fast, it would take you half the time. Half of 6, 6/2=<<6/2=3>>3 hours in total.
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