Seven boxes viz. S, T, U, V, W, X and Y are kept one above other in the form of stack. How many boxes are kept above box W?

I. Only two boxes are kept between box T and box X. Only three boxes are kept above box V. Box T and V are kept together. Only one box is kept between box W and box Y. Box S is neither kept at bottom nor adjacent to box T.

II. Box U is kept second from top. Box W is kept at any place above box Y. Only three boxes are kept between box X and box U. Box V, which is neither kept adjacent to box U nor box X, which is kept at s gap of two box from S. Box T doesn’t kept adjacent to box X but kept at any place below box S.

Solution

From I: We have:  Only three boxes are kept above box V. Box T and V are kept together. Only two boxes are kept between box T and box X Only one box is kept between box W and box Y. Box S is neither kept at bottom nor adjacent to box T, that means box S is kept at top and box X is kept below box T. Based on above given information we have: Clearly, we don’t know exact position of box W. Hence, statement I is not sufficient. From II: We have:  Box U is kept second from top. Only three boxes are kept between box X and box U, that means box X is kept second from bottom. Box V, which is neither kept adjacent to box U nor box X, which is kept at s gap of two box from S, that means box V is kept fourth from bottom. Box T doesn’t kept adjacent to box X but kept at any place below box S, that means box S is kept at top.  Box W is kept at any place above box Y, that means box Y is kept at bottom. Clearly, only four boxes are kept above box W. Hence, statement II alone is sufficient.