Amazon calculates a product's star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers and factors that establish reviewer trustworthiness.
Good book, has a plenty of logical questions along with examples easy to understand and great theory .A must have book for students of class 10.Go for it without any secondary thought . Its length is of 937 printed pages and is ultra new edition. Thanks for reading. Hope it's helpful .