Bunuel wrote:

Official Solution:

Whatever the value of \(x\), the first exchange turned 1000 dollars into the equivalent of \(1000(1 - \frac{y}{100})\) dollars. This amount, in turn, became \(1000(1 - \frac{y}{100})^2\) dollars after the second exchange. To answer the question we need to know the value of \(y\).

Statement (1) by itself is insufficient. S1 tells us the value of\(x\), not \(y\).

Statement (2) by itself is sufficient. S2 tells us the value of \(y\).

Answer: B

Adding to bunuel's solution

exchange rate X must be equal to a fraction i.e. [pound][/dollar] or [p][/d] .

Now after first conversion the amount would be = \(1000(1 - \frac{y}{100})\) . [p][/d]

Now when we convert again the pound to dollar the fraction would be inverted to [d[/p]

and the new dollar value that would be remaining = \(1000(1 - \frac{y}{100})^2\) . [p][/d] . [d[/p] = \(1000(1 - \frac{y}{100})^2\)

=> the Answer is B, as we just need to know the value of Y .