This is an interesting question with a fair bit of logical reasoning built into the question.
An approach that always works in such questions is to use the number line to represent the prices and determine the exact positions of each item. The following diagrams depict how this can be done:
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3rd Dec 2019 - Reply 1.jpg [ 47.9 KiB | Viewed 6047 times ]
If
a particular radio is the 15th highest, it means that
there are 14 radios above it in terms of price; similarly,
there are 19 radios that are
below it since the
same radio is the 20th lowest.
Therefore, total number of radios = 14 + 1 + 19 = 34.
Similarly, if
a particular DVD player is the
29th highest article, it means that
there are 28 articles above it in terms of price; similarly,
there are 36 articles that are below it since the
same DVD player is the 37th lowest article.
Therefore, total number of articles = 28 + 1 + 36 = 65.
Of 65 total articles, if 34 are radios, the remaining 31 have to be DVD players.
The correct answer option is B.
Hope that helps!