Exercise :: Problems on Ages  Data Sufficiency 2
 Problems on Ages  Important Formulas
 Problems on Ages  General Questions
 Problems on Ages  Data Sufficiency 1
 Problems on Ages  Data Sufficiency 2
 Problems on Ages  Data Sufficiency 3
Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.
1. 


Answer: Option D Explanation: II. Let the present ages of Arun and his son be 11x and 6x years respectively. I. 5 years ago, Arun's age = 2 x His son's age.
Clearly, any two of the above will give Arun's present age. Correct answer is (D). 
2. 


Answer: Option A Explanation: I. Let Ravi's present age be x years. Then, his father's present age = 2x years.
III. Ravi is younger than his brother.
Thus, I and II together give the answer. Clearly, III is redundant. Correct answer is (A). 
3. 


Answer: Option E Explanation: I. Let the present ages of Tanya and Rahul be 3x years and 4x years. II. After 5 years, (Tanya's age) : (Rahul's age) = 4 : 5. III. (Rahul's age) = (Tanya's age) + 5.
Tanya's age = 3x can be found. Thus, I and II give the answer. From I and III, we get 4x = 3x + 5. This gives x. Tanya's age = 3x can be found. Thus, I and III give the answer. From III : Let Tanya's present age be t years. Then Rahul's present age = (t + 5) years.
Thus, II and III give the answer. Correct answer is (E). 