The circumference of circle X is 1/2 the circumference of circle Y. Wh

Question

The circumference of circle X is 1/2 the circumference of circle Y. What is the area of circle X?

(1) The area of circle Y is  100\pi  ft^2.
(2) The circumference of circle Y is  20\pi  ft

Gladiator59 · Answer

Since we know the relationship between R1 and R2 of the two circles..

2*pi*R2 = 0.5 * 2*pi*R1

Anything that gives R1 will give us R2.

Hence option (D) is our answer without solving for the actual values of anything.

Best,
Gladi

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rohitf23 · Answer

Answer is B
1 stmt gives 2 output
2 stmt gives correct radius which will be calcuated for Area of Circle X

chetan2u · Answer

Yes statement 1 gives two output .. r^2 = 100...  r = 10 or -10
But we are looking at radius and it cannot be NEGATIVE so r = 10
suff

AV24 · Answer

Cx = 2 pi r
Cy = pi r

Statement 1
Ay=100 pi
also, Ay=C^2/4 pi ==> 100 pi = pi^2 r^2/4 pi ==>r = +/- 20, but radius will be positive so r=20

Statement 2

gives us the same info as statement 1

Cy=20 pi = pi r ==> r=20

Therefore ans is D

push12345 · Answer

2πx=(1/2)*2πy
X=y/2

1) get value of y using πr^2
Then calculate x 
Sufficient

II)get value of y using 2πr 
Then calculate x
Sufficient

Answer D

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