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1mile = 5280 ft
20mile = x ft
x ft = 20 * 5280 = 105600 ft
change from ft to in
1ft = 12 in
105600ft = x in
x in = 12 *105600
x in = 1267200 in
change from in to cm
1in= 2.54 cm
1267200in = x cm
x cm = 3218688 cm
finally we will change from cm to km
1km = 100000cm
x km = 3218688 cm
x km = 32.18688