To solve this problem you must apply the proccedure shown below:
1. You have that Boris had [tex] 2/3 [/tex]of a book left to read and he read [tex] 1/6 [/tex] of the book today.
2. Kepping this on mind, you must substract both fractions, as following:
[tex] =2/3-1/6\\ =1/2 [/tex]
3. Therefore, the answer is: Boris has [tex] 1/2 [/tex] of the book left to read.
