IBPS PO Exam 2011 Solved Paper

From statement I.
B and D are sisters of M
+ indicates Male

– indicates Female
From statement II.
M's father T is husband of W

From statement III
Out of the three children which T has, only one is a boy.

From statements II and III
Since W is the wife of T, Hence W has 2 daughters

So, II and III, are required to answer the question.