Answer:
51.7mm
Explanation:
#Find the minimum bound of the back/front thickness:
-Given that it's rounded to one decimal point, the margin or error will be:
![ME=(1)/(2)*0.1\\\\=0.05](https://img.qammunity.org/2021/formulas/mathematics/college/mlnrexjvyq6n16wyny52yq4e3c820ocn8i.png)
We subtract this ME from the front thickness to get the minimum thickness:
![M_t=0.9-0.05\\\\=0.85\ mm](https://img.qammunity.org/2021/formulas/mathematics/college/i7ubdwfp85h7ox6j7gpukzktqux0k0mqig.png)
#Find the minimum bound of the pages:
-Given that it's rounded to one decimal point, the margin or error will be:
![ME=(1)/(2)*0.01\\\\=0.005](https://img.qammunity.org/2021/formulas/mathematics/college/iglaqg6y2bl7zwfajznjwvzcq9vdrlolfj.png)
We subtract this ME from the page thickness to get the minimum thickness:
![M_p=0.13-0.005\\\\=0.125\ mm](https://img.qammunity.org/2021/formulas/mathematics/college/kqlef513c3jwjywabi19rt6pa11zxxx3b5.png)
The minimum book thickness is thus calculated as:
![M_[bt}=2* M_t+400* M_p\\\\=0.85* 2+400* 0.125\\\\=51.7\ mm](https://img.qammunity.org/2021/formulas/mathematics/college/p2tkgorrsy4ci74pvodddn1uce1cnxghvx.png)
Hence, the minimum thickness of the book is 51.7 mm