We're given 4 boxes—blue, yellow, green, and mauve(?). Yellow and green are stacked perfectly atop each other. Blue is to the left of yellow and the same height; mauve is to the right of green and the same height. The area of yellow is 28 sq. cm; the area of mauve is 14 sq. cm. The long length of blue + yellow is 9 cm; the long length of green + mauve is 10 cm; the height of mauve and green is 5 cm. That's all we know, and we have to solve for the area of blue.
Since we know the height and area of mauve, let's start there.
5x = 14
x = 14/5
The short side of mauve is 14/5, and the total length of the long side of green + mauve is equal to 10, so the long side of green is:
10 - (14/5) = 36/5
To find the height of yellow, then, we go
(36/5)x = 28
x = 35/9
That's the height of the blue rectangle as well.
The long length of blue + yellow is 9, and we know the long length of just yellow is 36/5, so to find the short length of blue, we go
x + 36/5 = 9
x = 9/5
We now know the two dimensions we need to calculate the area of blue.
All comments are subject to approval before they are published, so they will not appear immediately. Comments should be civil, relevant, and substantive. Anonymous comments are not allowed and will be unceremoniously deleted. For more on my comments policy, please see this entry on my other blog.
AND A NEW RULE (per this post): comments critical of Trump's lying must include criticism of Biden's or Kamala's or some prominent leftie's lying on a one-for-one basis! Failure to be balanced means your comment will not be published.
We're given 4 boxes—blue, yellow, green, and mauve(?). Yellow and green are stacked perfectly atop each other. Blue is to the left of yellow and the same height; mauve is to the right of green and the same height. The area of yellow is 28 sq. cm; the area of mauve is 14 sq. cm. The long length of blue + yellow is 9 cm; the long length of green + mauve is 10 cm; the height of mauve and green is 5 cm. That's all we know, and we have to solve for the area of blue.
ReplyDeleteSince we know the height and area of mauve, let's start there.
5x = 14
x = 14/5
The short side of mauve is 14/5, and the total length of the long side of green + mauve is equal to 10, so the long side of green is:
10 - (14/5) = 36/5
To find the height of yellow, then, we go
(36/5)x = 28
x = 35/9
That's the height of the blue rectangle as well.
The long length of blue + yellow is 9, and we know the long length of just yellow is 36/5, so to find the short length of blue, we go
x + 36/5 = 9
x = 9/5
We now know the two dimensions we need to calculate the area of blue.
(35/9)•(9/5) = 35/5 = 7.
The area of blue is 7 sq. cm.
QED.