Answer :
Given:
[tex]\frac{1}{6} \text{ book in } \frac{2}{3} \text{ hours}[/tex]
To find:
Number of books per hour
Solution:
We have to calculate the book read in one hour.
[tex]\frac{1}{6}\text{ book }\rightarrow\frac{2}{3}\text{ hour}\\\\\text{we have to multiply both the side with 2/3}\\\\\frac{1}{6}\times\frac{3}{2}\text{ book }\rightarrow\frac{2}{3}\times\frac{3}{2}\text{ hour}\Rightarrow\frac{1}{4}\text{ book }\rightarrow1\text{ hour}[/tex]
Therefore, we can conclude that the answer is [tex]\bold{\frac{1}{4}\text{ book }\rightarrow1\text{ hour }}[/tex] which is option B.