On which day of the week was birthday of Arjun if week is starting from Monday?
(I) Arjun celebrated his birthday the very next day on which Sahil celebrated his birthday.
(II) The sister of Arjun was born on the fifth day of the week and two days after Arjun was born.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → if the data in statement II alone are sufficient to answer the question
A statement is sufficient only if it fixes one day for Arjun’s birthday.
Statement I alone — Arjun’s birthday is the day after Sahil’s, but Sahil’s day is not given, so the day cannot be found. Not sufficient.
Statement II alone — the week starts on Monday, so the fifth day is Friday: Arjun’s sister was born on a Friday. She was born two days after Arjun, so Arjun was born two days before Friday, on Wednesday. Sufficient.