<span>15 silver keys,
5 black keys,
11 copper keys,
4 painted
35 total
15 + 11 = 26
26/35 = 0.7428 </span>≈ 74.28% probability
Still begging? OK. Let's do it with algebra first then put in the numbers.
We're given the Circumference of a circle C, and we want the area A.
The radius is related to the circumference by
C = 2π r
The area is related to the radius by
A = π r²
Solving for r in the first equation,
r = C/(2π)
So the area is
A = π ( C/(2π) )² = πC²/(4π²) = C²/(4π)
---------------------------
OK we're given C=25 1/7 inches, π≈22/7
C = (7×25 + 1)/7 = 176/7 = (22×8)/7
That's a little convenient.
A = C²/4π = ( (22×8)/7 )² / (4 (22/7) ) = (8²/4) (22/7) = (16*22)/7 = 352/7
After those nice numbers they want an approximation. How disappointing.
A = 50.2857142857 sq inches
Answer: 50.29
Answer:
I think its about 9? being as if you look a it its close to 12 but nowhere near it.
