Who among P, Q, R, S, T and U is the tallest, considering that all have different heights?
I. Q is taller than P but shorter than T.
II. Only two of them are shorter than R.
III. S is taller than only U.
All I, II and III are required to answer the question
By combining Statements I, II and III,
Hence, T is the tallest.
So, all Statements I, II and III are necessary to answer the question.