2023 · Q44
Assume that the Earth is a spherical ball of radius x km with a smooth surface so that one can travel along any direction. If you have travelled from point P on the Earth's surface along the East direction a distance of πx km, which direction do you have to travel to return to P so that the distance required to travel is minimum?
general-mental-abilityquantitative-aptitude
- AEast only
- BWest only
- CEast or West but not any other direction
- DAny fixed direction
Explanation
Travelling pi.x km eastward on a sphere of radius x covers exactly half the great-circle circumference (2.pi.x), so the traveller reaches the antipodal point of P. From the antipode, every great-circle direction leads back to P over the same minimum distance of pi.x km. Hence the traveller may return by travelling in any fixed direction, which is option D.