1. The problem statement, all variables and given/known data A water tank is 4 meters deep. A candle flame is kept 6 metres above the level of the water. Mu for water is 4/3. Where will the image of the candle be formed? 2. Relevant equations 3. The attempt at a solution I need a few clues to proceed. If I consider refraction at the water surface the image will be formed above the candle flame. The answer given in the book is 6 metres below the water level.