Answer
100 wavelengths.
Work Step by Step
In Example 1–7 the thickness of a page of the textbook is about found to be $6 \times 10^{-5} m$. We also know that 1,650,763.73 wavelengths of orange krypton-86 light fit in one meter.
$$(1 page)(\frac{6 \times 10^{-5} m}{page})(\frac{1,650,763.73 wavelengths}{m}) = 99$$ wavelengths.
Only one significant figure should be kept in the quotient.
