Chapter 1 - Measurement and Problem Solving - Learning Path Questions and Exercises - Exercises - Page 31: 58

$a). 0.0087 cm$ $b). 0.87 \times 10^{-2} cm$

a). A single page has 2 page numbers. So, there are $\frac{860}{2}=430$ pages. Average thickness$= \frac{3.75 cm}{430}= 0.0087 cm$ b). Average thickness$ = \frac{3.75}{430}=\frac{0.375\times 10}{0.430\times 10^{3}}=0.87\times 10^{-2}cm$