The book is a new edition of a bestseller by an experienced coach Sergey Ivashchenko. Over 250,000 copies of his books were sold in the Soviet Union in the late 1980's.
This book is intended for beginners, both children and adults. The themes are: Win a piece, Draw, etc.
The book designed for chess players with ELO 1200-1500 points. Includes more than 600 tactical problems classified according to themes and difficulty.
This book and the previous 1a book make an outstanding "fast tactics for mass practice" set. I loaded the positions into a PGN file and then sped them through using a tactics app (an example is iChess - on both Apple and Android). Well selected "easy" positions makes recognizing patterns much more automatic - and this 1a/1b set is just right for 3-5 seconds per position. My only complaint is that some of the positions have multiple equally good answers. This is not a problem if you are solving from the book, but it confuses simple non-engine backed apps.