<prompt> A problem village is one wrhere -Source of water 1?6 km awayWater available 15 meters depthExcess of fluoride in waterAll of the above  <response>: Ans. is i.e., All of the above o A problem village has been defined as oneWhere no source of safe water is available within a distance of 1.6 km, or Where water is available at a depth of more than IS meters, orWhere water source has excess salinity, iron, fluorides and other toxic elements, orWhere water is exposed to the risk of cholera. 