Answer:
53.8 mm
Step-by-step explanation:
Front page and a back page + 400 pages.
The front and back cover are each 0.9mm thick, measured to 1 decimal place.
Total thickness of front and back page = 0.9mm × 2
= 1.8 mm
Each page is 0.13mm thick measured to 2 decimal places
Total number of pages = 400
Total thickness of the pages = Thickness of each page × Total number of pages
= 0.13mm × 400
= 52 mm
minimum thickness of the book = Total thickness of front and back page + Total thickness of the pages
= 1.8mm + 52mm
= 53.8 mm
The minimum thickness of the book is 53.8 mm
