Question

The average age of P, Q, R and S is $30years$. How old is R?
I. The sum of ages of P and R is $60years$.
II. S is $10$ years younger than R.

• A. I alone sufficient while II alone not sufficient to answer
• B. II alone sufficient while I alone not sufficient to answer
• C. Either I or II alone sufficient to answer
• D. Both I and II are not sufficient to answer
• E. Both I and II are necessary to answer

Answer 1

Answer: (D)

Both I and II are not sufficient to answer

$P+Q+R+S=(30\times 4)\Rightarrow P+Q+R+S=\mathrm{120....}\left(i\right)$
I. $P+R=60....\left(ii\right)$
II. $S=(R-10)....\left(iii\right)$
From (i), (ii) and (iii), we cannot find R.
$\therefore$ Correct answer is (D).