To find the ratio of non-fiction books to science-fiction books, we first need to identify the number of each type of book Ashleigh read.
According to the information provided:
- Non-fiction books: 50
- Science-fiction books: 30
Now, we can express the ratio of non-fiction books to science-fiction books as follows:
\[\text{Ratio} = \frac{\text{Number of non-fiction books}}{\text{Number of science-fiction books}} = \frac{50}{30}\]
To simplify this ratio, we can divide both the numerator and the denominator by 10:
\[\frac{50 \div 10}{30 \div 10} = \frac{5}{3}\]
Thus, the ratio of non-fiction books to science-fiction books is \(5:3\).
The correct answer is: B. 5 to 3