Answer:
Bob will have a total of 54 books
Explanation:
Step 1: Determine number of books per shelf
Using the expression below;
T=b×n
where;
T=total number of books
b=number of books per shelf
n=number of book shelf
In our case;
T=27 books
b=unknown
n=3
replacing;
27=b×3
3 b=27
b=27/3
b=9
Consider, when T=36, and n=4
36=b×4
b=36/4
b=9 books per shelf
It is determined that a shelf holds a standard of 9 books
Step 2: Total number of books
Using the expression;
T=b×n
where;
b=9 books per shelf
n=(4+2)=6 shelf
replacing;
T=(9×6)=54 books
Bob will have a total of 54 books