From a circular sheet of paper with a radius of 20cm four circles of radius 5cm each are cut out

area of the larger circle=3.14*(20)^2
area of the smaller circle=3.14*(5^2)
total area of 4 smaller circles=4*3.14*(5^2)
so uncut portion={3.14*(20)^2}-{4*3.14*(5^2)}=3.14*300
ratio of uncut to cut=3.14*300/4*3.14*(5^2)=3:1
13 years agoHelpfull: Yes(12) No(0)
Area of the circular sheet with a radius of 20cm(A)=22/7 * 20^2=8800/7,
Area of the circle with radius 5cm(a)=22/7 *5^2=550/7,
So,Area of the 4 circles with radius 5cm(B)=4*a=4*550/7=2200/7,
Then, uncut area=A-B=8800/7 - 2200/7 =6600/7,
Therefore, the ratio of the uncut to the cut portion = 6600/7 : 2200/7 = 3:1
13 years agoHelpfull: Yes(6) No(1)
3:1
13 years agoHelpfull: Yes(1) No(3)
3:1
total area of cut=5*pi*25
total uncut area=pi*(400-125)=pi*275
so 3:1
13 years agoHelpfull: Yes(1) No(1)
total area=PI*20^2=1256.64SQ. CM

AREA OF EACH CIRCLE = PI*5^2=78.5 SQ. CM
AREA OF CIRCLES OF 5CM RADIUS IS = 314.16 CM2

SO AREA OF UNCUT PART = 1256.64-314.16 =942.48 SQ. CM

SO RATIO OF UN CUT TO CUT PORTION IS = 942.48/314.16 =3:1

ANS: (C)
13 years agoHelpfull: Yes(1) No(0)
area of uncut=(400-100)3.14
area of cut=4*25*3.14=(100)3.14
ratio=3:1
ans=3:1
9 years agoHelpfull: Yes(0) No(0)

From a circular sheet of paper with a radius of 20cm,four circles of radius 5cm each are cut out.what is the ratio of the uncut to the cut portion?
(A)1:3 (B)4:1 (C)3:1 (D)4:3 (E)2:3