A parasailis 1/20 of a kilometer above the water. Then, after 10 minutes, the parasailis 1/50 of a kilometer above the water. What is the change in height? (1 point)

3/100 kilometers

7/100 kilometers

1/50 kilometers

1/20 kilometers

1 answer

To find the change in height of the parasail, we need to subtract the initial height from the final height.

The initial height is \( \frac{1}{20} \) of a kilometer and the final height is \( \frac{1}{50} \) of a kilometer.

First, we need to convert these fractions to have a common denominator in order to subtract them easily.

The least common multiple of 20 and 50 is 100.

Now we convert both heights:

  1. For \( \frac{1}{20} \): \[ \frac{1}{20} = \frac{5}{100} \]

  2. For \( \frac{1}{50} \): \[ \frac{1}{50} = \frac{2}{100} \]

Now, we can calculate the change in height:

\[ \text{Change in height} = \text{Final height} - \text{Initial height} = \frac{2}{100} - \frac{5}{100} = \frac{2 - 5}{100} = \frac{-3}{100} \]

Since the change in height is negative, it indicates a decrease in height.

However, we want the absolute value to represent the change in height:

\[ \text{Change in height} = \frac{3}{100} \text{ kilometers} \]

Thus, the change in height is \( \frac{3}{100} \) kilometers.

The answer is \( \frac{3}{100} \) kilometers, which is not among the options you provided. However, based on the options given, the closest representation of this change is:

3/100 kilometers.