Machine-translated by Google. Questions are authored in English.
Top

Discussion

If A + B = C + D and A + D > B + C, then which one of the following is wrong ?

  • A.A > B
  • B.A > C
  • C.C > D
  • D.B > D

Answer: D

The statement that is wrong is B > D.

Rearrange the two conditions:

\[ \begin{aligned} A + B = C + D &\Rightarrow A - C = D - B \\ A + D \gt B + C &\Rightarrow A - C \gt B - D \end{aligned} \]

Substituting the first into the second gives \(D - B \gt B - D\), so \(D \gt B\). Therefore B > D must be wrong. It also follows that \(A - C = D - B \gt 0\), so A > C is true.

A > B and C > D are not fixed by the data either way, so they cannot be called wrong; only B > D contradicts the conditions.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.