To find the number represented by point B on the number line that goes from 1 to 2, we first need to determine the increments between the marks on the number line.
Since there are 5 equal spaces between 1 and 2, we can calculate the length of each interval:
\[ \text{Interval length} = \frac{2 - 1}{5} = \frac{1}{5} \]
Now, we will mark the numbers between 1 and 2:
- The first mark is at \(1 + \frac{1}{5} = \frac{6}{5}\) (or 1.2).
- The second mark is at \(1 + 2 \cdot \frac{1}{5} = \frac{7}{5}\) (or 1.4).
- The third mark is at \(1 + 3 \cdot \frac{1}{5} = \frac{8}{5}\) (or 1.6).
- The fourth mark is at \(1 + 4 \cdot \frac{1}{5} = \frac{9}{5}\) (or 1.8).
- The fifth mark is at \(1 + 5 \cdot \frac{1}{5} = 2\).
Point B is described as being one mark to the left of 2. Since the position of 2 is the fifth mark, one mark to the left of 2 is the fourth mark:
Thus, the value at point B is:
\[ 1 + 4 \cdot \frac{1}{5} = \frac{9}{5} \]
Therefore, point B is represented by:
\[ \frac{9}{5} \]
Now, let's check the options against this value:
- \( \frac{4}{5} \) is equivalent to 0.8
- \( 1 \frac{4}{5} \) is equivalent to 1.8
- \( 1 \frac{5}{4} \) is equivalent to 2.25
- \( 2 \frac{1}{5} \) is equivalent to 2.2
As we can see, \( \frac{9}{5} \) equals \( 1.8 \), which is \( 1 \frac{4}{5} \).
Thus, the answer that represents point B is:
\[ 1 \frac{4}{5} \]