which is similar to n:1 where 
<u>Step-by-step explanation:</u>
Here we have to Express in the form n:1 give n as a decimal 21:12 . Let's find out:
Given ratio as 21:12 . Let's convert it into n:1 , where n is decimal
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{ dividing denominator & numerator by 4 }
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which is similar to n:1 where 
Answer: x-3, 3, is not equal to
Step-by-step explanation:
Three miles a day should be the correct answer
The first one = 60.3 so it can’t be that one.
the second one = 34.5 so not that one either
the third one = 60.3
and the last one = 28.3
R=12.13
A=pi×r²
A=pi×12.13²
A≈462.2442041
A≈462.2 (to the nearest tenth).
So the answer is A≈462.2.