Discussion Forum



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

1)

How much money did $X$ invest ?

I. An increase in the rate of invest from $4\frac{7}{8}\%$ to $5\frac{1}{8}\%$ per annum increase his yearly income by Rs. $25$.

II. The sum invested gets doubled, when invested at $8\%$ p.a for $12\frac{1}{2}$ years.


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:

Option A

Explanation:

Suppose $X$ invests Rs. $x$.

I gives : $R_{1}$ $=\frac{39}{8}\%$, $R_{2}$ $=\frac{41}{8}\%$.

Increase in $SI$ = Rs. $25$.

$\Rightarrow \left(\frac{x\times 1\times\frac{41}{8}}{100}\right)$ $-\left(\frac{x\times 1\times\frac{39}{8}}{100}\right)$ $=25$

$\Rightarrow (41x-39x)$ $=(25\times 800)$ $\Rightarrow x$ $=\left(\frac{25\times 800}{2}\right)$ $=10000$.

Thus, I only gives the answer.

II gives, $SI$ = Rs. $x$, $R=8\%$ and $T=\frac{25}{2}$ years.

$P$ $=\frac{100\times SI}{R\times T}$ $=\left(\frac{100\times x}{8\times 25}\times 2\right)$

Thus, $P$ is not obtained.

$\therefore$ I alone is sufficient to get the answer and II is not sufficient to get the answer.

$\therefore$ Correct answer is (A).