XAT 2018 — QA & DI Question 20
These statements provide data that may help answer the respective questions. Read the questions and the statements and determine if the data provided by the statements is sufficient or insufficient, on their own or together, to answer the questions. Accordingly, choose the appropriate option given below the questions.
A group of six friends noticed that the sum of their ages is the square of a prime number. What is the average age of the group?
Statement I: All members are between 50 and 85 years of age.
Statement II: The standard deviation of their ages is 4.6.
Answer & solution
Statement I alone is sufficient to answer.
- B
Statement II alone is sufficient to answer.
- C
Either of the statement is sufficient to answer.
- D
Both statements are required to answer.
- E
Additional information is required.
From statement I:
Sum of their ages lies between (6 × 50) and (6 × 85), i.e., 300 and 510.
The only square of a prime number in this range is 192 = 361.
∴ The average of their ages = 361/6.
Hence, the question can be answered using statement I alone.
From statement II:
Standard Deviation = 4.6 =
Since there are two unknowns here, the question cannot be answered using this statement alone.
Hence, option (a).