15.
P, Q, R, S, T and U are six siblings who passed their class tenth exam in different years viz. 2001, 2003, 2005, 2007, 2010 and 2012 but not necessarily in the same order.
P passed in one of the years before S and after R. Only Q passed before R. T passed in the year immediately after S. U passed in one of the years before P. Who passed their class tenth exam in the year 2007?