In the question below consists of a question and two statements numbered a and b given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and give the answer. Question: In which year was Kalyan born ? Statements: a. Kalyan at present is 15 years younger to his mother. b. Kalyan's brother, who was born in 1991, is 25 years younger to his mother.

• b alone is sufficient while a alone is not sufficient
• a alone is sufficient while b alone is not sufficient
• Both a and b are sufficient
• Neither a nor b is sufficient