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Venu starts from Point Y and drives 7 km towards south. He then takes a left turn, drives 15 km, turns right and drives 38 km. He then takes a left turn and drives 13 km. He takes a left turn, drives 31 km. He then turns left, drives 28 km, turns left and drives 13 km to stop at Point Z. How far (shortest distance) and towards which direction should he drive in order to reach Point Y again? (All turns are 90 degrees turns only unless specified)
24 km towards south
28 km towards east
20 km towards south
27 km towards north
27 km towards north
Track Venu's journey on a 2D Cartesian coordinate plane to find relative position of Point Z to Point Y
Define Coordinate Axes
Let Point Y be at the origin (0,0). Let North = +y, South = тИТy, East = +x, West = тИТx.
Trace Each Segment
тАв Drives 7 km South: (0,тИТ7), facing South тАв Turns left (East)тВБтВЕ km: (15,тИТ7), facing East тАв Turns right (South)тВГтВИ km: (15,тИТ45), facing South тАв Turns left (East)тВБтВГ km: (28,тИТ45), facing East тАв Turns left (North)тВГтВБ km: (28,тИТ14), facing North тАв Turns left (West)тВВтВИ km: (0,тИТ14), facing West тАв Turns left (South)тВБтВГ km to Z: (0,тИТ27), facing South
Calculate Return Vector to Point Y
Point Z is at (0,тИТ27) and Point Y is at (0,0). The vector from Z to Y is ╬Фx=0, ╬Фy=0тИТ(тИТ27)=+27┬аkm. This corresponds to 27 km directly towards North.
Venumustdrive27kmtowardsNorthtoreachPointY.
27 km towards north