Discussion Forum



Each of the questions given below consists of a statement and/ or a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statement(s) is / are sufficient to answer the given question.

  • Mark answer (A) if (I) alone sufficient while (II) alone not sufficient to answer
  • Mark answer (B) if (II) alone sufficient while (I) alone not sufficient to answer.
  • Mark answer (C) if Either (I) or (II) alone sufficient to answer.
  • Mark answer (D) Both (I) and (II) are not sufficient to answer.
  • Mark answer (E) Both (I) and (II) are necessary to answer.
1)

How old is Z now?

I) Three years ago, the average of X and Y was 18 years

II) With Z joining them now, the average becomes 22 years.


A) I) alone sufficient while II) alone not sufficient

B) II) alone sufficient while I) alone not sufficient

C) Either I) or II) alone sufficient

D) Both I) and II) are not sufficient

E) Both I) and II) are necessary

Answer:

Option E

Explanation:

I) $3$ years ago, $\frac{1}{2}(X+Y)=18$

$\Rightarrow 3$ years ago, $(X+Y)=36$

Now, $\frac{1}{3}$ $=(36+3+3)$

$=42$ $\Rightarrow (X+Y)=42$---(1)

II) Now, $\frac{1}{3}(X+Y+Z)=22$

$\Rightarrow X+Y+Z = 66$ ---(2)

From I and II, we get $Z - (66-42)$ $=24$

Thus, I and II both together give the answer. So, correct asnwer is (E).