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?
To find out how long it will take Charla to complete the entire picture, we can use the unitary method.
Let's say the time it takes her to complete the entire picture is 't' hours.
According to the information given, completing 2/3 of the area takes 1/2 hour.
So, in 't' hours, Charla will complete the entire area.
Therefore, we can set up the following proportion:
(2/3) area : (1/2) hour = 1 (entire area) : t (hours)
Cross multiplying, we get:
(2/3) * t = (1/2)
Now, we can solve for 't' by multiplying both sides by the reciprocal of (2/3), which is (3/2):
t = (1/2) * (3/2)
t = 3/4
Therefore, it will take Charla 3/4 of an hour, or 45 minutes, to complete the entire picture.
Since Charla completes 2/3 of the area in 1/2 hour, then 1/3 of the area will take 1/2 hour \* 3/2 = <<1/2*3/2=0.75>>0.75 hour.
So, the entire picture will take her 0.75 hour x 3 = <<0.75*3=2.25>>2.25 hours. Answer: \boxed{2.25}.
To find out how long it will take Charla to complete the entire picture, we can set up a proportion using the information given.
Let's say the entire rectangular area of the driveway is represented by the fraction 1. The area Charla completes in 1/2 hour is 2/3 of the total area.
So, we have the proportion:
(2/3) / (1/2) = 1 / x
To solve for x, we can use cross multiplication:
(2/3) * x = (1/2) * 1
2x / 3 = 1/2
Now, to isolate x, we can multiply both sides of the equation by 3/2:
(2x / 3) * (3 / 2) = (1/2) * (3 / 2)
2x / 2 = 3 / 4
x = 3 / 4
Therefore, it will take Charla 3/4 of an hour to complete the entire picture on her driveway.