This problem proposed by Professor Qi Feng from the book《MARSHALL A W, OLKIN I, ARNOLD B C. Inequalities: theory of majorization and its application (Second Edition) [M]. New York : Springer Press, 2011.》pp.295-296.
This problem was asked in a Tencent QQ Group (an online communicating software) by Professor Huan-Nan Shi (retired) at Beijing Union University in China. Then, by granting from Professor Shi, I forwarded this problem here. Thank all.
The question should be corrected as the one showed in the picture uploaded in this message. The answer should be the one at https://www.researchgate.net/file.PostFileLoader.html?id=5786c728eeae39193e6c6525&assetKey=AS%3A383523769864192%401468450600742