Word Problem -The temperature of a place at noon on a certain day is 2

Hey,

PFB the official solution.

Steps 1 & 2: Understand Question and Draw Inferences

Let temperature at midnight be \(M\).
And, temperature at noon be \(N\).

Given:

\(N = (1 + \frac{25}{100})M = \frac{125}{100} * M = \frac{5}{4} * M\) . . . (I)

We need to find the value of\(M\).

We already have \(1\) equation between \(N\) and \(M\). If we have one more equation between \(N\) and \(M\), we can find a unique value of \(M\).


Step 3: Analyze Statement 1 independently

Statement 1 says that

\(M = (1 – \frac{20}{100})N = \frac{80}{100} * N = \frac{4}{5} * N\)

This equation restates what we already know from Equation (I). So, not sufficient.


Step 4: Analyze Statement 2 independently

Statement 2 says that

\(N = M + 10\) . . . (II)

We now have one more equation between \(N\)and \(M\). So, Equations (I) and (II) are sufficient to find a unique value of \(M\).


Answer: B

Thanks,
Saquib
Quant Expert
e-GMAT

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