GRE exam question

If the radius of a circle is decreased by 50%, find the percentage decrease in its area. A) 55% B) 65% C) 75% D) 85%

47 Answers

Let r1 = 100br /Then r2 = 50br /br /A1 = π × 1002 = 10000πbr /A2 = π × 502 = 2500πbr /br /Decrease in area = 10000π - 2500π = 7500πbr /br /Percentage decrease in area = 7500π×10010000π=75%
- Mohammad
- 06 Jul
- 0 Comment
0
75
- Sahil
- 28 Jun
- 0 Comment
0
A
- Ashwin
- 23 Jun
- 0 Comment
0
75
- Archana
- 22 Jun
- 0 Comment
0
75
- Karamvir
- 05 Jun
- 0 Comment
0
75
- Maaz
- 31 May
- 0 Comment
0
let's suppose area of circle is 3.142×r^2 then after radius is reduced by 50% then area of new circle will be 3.142*0.5r*0.5r=3.142*o.25*r^2 Percentage decrease= ((3.142*r^2-3.142*0.25*r^2)/3.14*r^2 )*100% =((1-0.25)/1)*100% =0.75*100% 75%
- Nupur
- 29 May
- 0 Comment
0
c
- Sneha
- 24 May
- 0 Comment
0
A1=A A2=.5*.5A=0.25A A1-A2=.75 .75*100=75%
- Bipin
- 03 May
- 0 Comment
0
C
- Niyati
- 31 Mar
- 0 Comment
0
C
- Khaja
- 21 Mar
- 0 Comment
0
C
- Madhusudhan
- 19 Jan
- 0 Comment
0
c
- Hatim
- 19 Jan
- 0 Comment
1
75
- Rajat
- 12 Dec
- 0 Comment
0
75
- Susmita
- 07 Dec
- 0 Comment
0
75%
- Sarvnish
- 26 Nov
- 0 Comment
0
c
- Md
- 20 Nov
- 0 Comment
0
75
- Kinal
- 20 Nov
- 0 Comment
0
75
- Battu
- 17 Nov
- 0 Comment
0
c
- Fifi
- 13 Nov
- 0 Comment
0

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