Data Sufficiency 2
6) How many brothers does Rahul have?
I. Rahul's father has three children.
From both the statements, we conclude that Rahul's father has three children and Rahul has one sister. It means Rahul has one brother. Thus, both I and II are needed to answer the question.
7) Deepak, Rahul, Manoj, and Kapil are brothers. Who is the heaviest?
I. Rahul is heavier than Deepak and Kapil, but lighter than Manoj.
From statement I alone, we conclude that Manoj is the heaviest. Statement II alone is not sufficient.
8) Sohan ranks fifth in the class. How many students are there in the class?
I. His friend ranks 52th which is the last rank in the class.
The statement I shows that 52th is the last rank in the class. It means there are 52 students in the class.
Statement II shows that Sohan ranks 48th from the last and it is also given that Sohan ranks fifth in the class. It means, there are (5+48-1) = 52 students in the class. Thus, either I or II is sufficient.
9) At what time did Rahul leave home for office?
I. Rahul had his breakfast at 9:20 am at home.
The statement I alone is not sufficient. The statement II reveals that Rahul left home 30 minutes before 10:20 am, i.e., at 9:50 am. So, statement II alone is sufficient.
10) When is Deepak's birthday?
I. Deepak's mother was born on 22 May 1970.
Even from both the statements together we cannot find Deepak's birthday. So, Neither I nor II is sufficient.
Data Sufficiency 1
Data Sufficiency 3
Data Sufficiency 4