If box O is placed immediate above of box A then box O is placed in which number rack? 

Box A is placed immediately above Box B. Three boxes are placed between Box B and the box has 180 fruits. Box which has 175 fruits is placed immediately above the box, which has 180 fruits. Only one box is placed between the boxes having 175 and 165 fruits. We get two possibilities with respect to above statements, Case-1: Box A and Box B is placed in 6th and 5th rack respectively. The box which has 180 fruits is placed in the lowermost rack. The box which has 175 fruits is placed in second rack. The box which has 165 fruits is placed in fourth rack. Case-2: Box A and Box B is placed in 2nd and 1st rack respectively. The box which has 180 fruits is placed in the 5th rack. The box which has 175 fruits is placed in topmost rack. The box which has 165 fruits is placed in fourth rack. By using above information we get the following table as shown Box D has 210 fruits. Box which has 119 fruits is placed immediately above the box which has 190 fruits. Two boxes are placed between the box which has 190 fruits and Box E. Box C is placed above Box F but neither of the boxes is placed in the topmost rack. From above statements, Box D has 210 fruits and it is placed in 3rd rack (only possibility in both cases) Case-1: The boxes which have 119 and 190 fruits are placed in 6th and 5th rack respectively. Box E is placed in second rack. Finally, Box C and Box F are placed in 4th and 1st rack respectively. All the given condition satisfied and we get the completed arrangement as shown, Case-2: The boxes which have 119 and 190 fruits are placed in 6th and 5th rack respectively. Box E is placed in second rack. Either Box C or Box F is not placed in the topmost rack. Thus this case-2 becomes invalid and it can be eliminated. By using above information we get the following table as shown,