Answer: b.14
Step-by-step explanation:
We have two shelves, the top shelf [tex]s_{t}[/tex] and the bottom shelf [tex]s_{b}[/tex].
Now, firstly we are told the top shelf has 10 more than 1/3 the number of books on the bottom shelf. This can be expressed as:
[tex]s_{t}=10+\frac{1}{3}s_{b}[/tex] (1)
Then, we are told there are 12 books on the bottom shelf:
[tex]s_{b}=12[/tex] (2)
Substituting (2) in (1):
[tex]s_{t}=10+\frac{1}{3}(12)[/tex] (3)
[tex]s_{t}=10+\frac{12}{3}[/tex] (4)
[tex]s_{t}=14[/tex] (5) This is the number of books on the top shelf
Hence, the correct option is b.
