Question

natsumi paints walls for a living. she paints at a constant speed, and then she takes a constant amount of time to clean up.
the table compares the total area natsumi paints (in square meters) and the time it takes natsumi to finish painting and cleaning up (in hours).
area (square meters) time (hours)
30 2
45 2.75
60 3.5
how long does it take natsumi to paint 1 square meter?
____ hours
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Explanation:

Step1: Find time difference for area change

First, calculate the change in time and area between two data points. Let's use the first two:
Area change: $45 - 30 = 15$ square meters
Time change: $2.75 - 2 = 0.75$ hours

Step2: Calculate time per square meter

Divide the time change by the area change to get time per 1 square meter.
$\frac{0.75}{15} = 0.05$
Verify with another pair (60-45=15 sq m, 3.5-2.75=0.75 hrs): $\frac{0.75}{15}=0.05$, consistent.

Answer:

0.05 hours