A flagpole is 20 feet tall and, in the afternoon, casts a shadow of 30 feet. At the same time, Keira casts a shadow of 7.5 feet. How tall is Keira? A. 3 feet. B. 4 feet. C. 5 feet. D. 5 feet
20' high : 30' shadow
? high : 7.5' shadow
This is a problem of direct proportions, the taller the object, the longer the shadow.
Keira's height can be found by cross multiplication,
H = 20*7.5/30 = 5 feet.
Also, please refrain from double posting the same problem within a short time. Allow some time for tutors to look at the problem.
To solve this problem, we can use ratios and proportions.
Let's denote the height of Keira as "x" feet.
We know that the ratio of the flagpole's height to its shadow length is the same as the ratio of Keira's height to her shadow length.
This can be expressed as:
(height of flagpole) / (length of flagpole's shadow) = (height of Keira) / (length of Keira's shadow)
Substituting the given values:
20 feet / 30 feet = x / 7.5 feet
To find the value of "x," we can cross-multiply:
20 feet * 7.5 feet = 30 feet * x
150 feet = 30 feet * x
To isolate "x," we divide both sides of the equation by 30 feet:
150 feet / 30 feet = x
5 feet = x
Therefore, Keira's height is 5 feet.
So the correct answer is C. 5 feet.