Charla wants to cover a certain rectangular area of her driveway with a picture using chalk. If she completes 2/3

of the area in 1/2
hour, how long will it take her to complete the entire picture

1 answer

To determine how long it will take Charla to complete the entire picture, we can first find the rate at which she covers the area.

Charla completes \( \frac{2}{3} \) of the area in \( \frac{1}{2} \) hour.

Step 1: Find the rate of area covered per hour.

If she completes \( \frac{2}{3} \) of the area in \( \frac{1}{2} \) hour, we can calculate her rate as follows:

\[ \text{Rate} = \frac{\text{Area completed}}{\text{Time}} = \frac{\frac{2}{3}}{\frac{1}{2}} \]

To divide by a fraction, we can multiply by its reciprocal:

\[ \text{Rate} = \frac{2}{3} \times \frac{2}{1} = \frac{4}{3} \]

This means she can complete \( \frac{4}{3} \) of the area in 1 hour.

Step 2: Calculate the total time for the entire area.

Since Charla can complete \( \frac{4}{3} \) of the area in 1 hour, we need to find out how long it takes to complete the whole area (1 full area).

Let \( T \) be the time in hours to complete the entire area:

\[ \text{Rate} \times T = 1 \]

Substituting the rate we found:

\[ \frac{4}{3} \times T = 1 \]

To solve for \( T \):

\[ T = \frac{1}{\frac{4}{3}} = \frac{3}{4} \text{ hours} \]

Step 3: Convert the time into minutes.

To convert \( \frac{3}{4} \) hours into minutes, we multiply by 60 minutes/hour:

\[ \frac{3}{4} \times 60 = 45 \text{ minutes} \]

Conclusion

It will take Charla 45 minutes to complete the entire picture.