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Bunuel
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In a survey it was found that 10% people don’t use Facebook, Twitter 28 Apr 2020, 02:15
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Difficulty:

55% (hard)

Question Stats:

73% (02:40) correct 27% (02:56) wrong based on 229 sessions

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Competition Mode Question



In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsap. 8% uses all the three. There are 15% who uses only Facebook and Twitter, 20% who use only Twitter and Whatsap and 20% who use only Facebook and Whatsap. Number of people that use only Facebook, only Twitter and only Whatsap are equal. If the survey was conducted on 1000 people, how many people use Whatsap only?

A. 9
B. 15
C. 20
D. 45
E. 90


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E
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In a survey it was found that 10% people don’t use Facebook, Twitter 28 Apr 2020, 04:51
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Nett Total = 1000 * 90% = 900 (since 10% don't use any F,T,W).

P(Twitter only) = P(T only) = x
P(Facebook only) = P(F only) = x
P(Whatapp only) = P(W only) = x

P(F n T n W) = 1000 * 8% = 80
P(F, T only) = 1000 * 15% = 150
P(T, W only) = 1000 * 20% = 200
P(F, W only) = 1000 * 20% = 200

Q. P(W only) ?

Nett total = x + x + x + 150 + 200 + 200 + 80

900 = 3x + 630
3x = 270
x = 90

--> the number of people who use Whatsap only is x=90

FINAL ANSWER IS (E)

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In a survey it was found that 10% people don’t use Facebook, Twitter 28 Apr 2020, 06:17
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Quote:
In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsap. 8% uses all the three. There are 15% who uses only Facebook and Twitter, 20% who use only Twitter and Whatsap and 20% who use only Facebook and Whatsap. Number of people that use only Facebook, only Twitter and only Whatsap are equal. If the survey was conducted on 1000 people, how many people use Whatsap only?

A. 9
B. 15
C. 20
D. 45
E. 90
Show more

total=a+b+c-both-2mid+neither
100=a+b+c-(20+20+15)-2(8)+10
161=a+b+c
a=x+20+20+8, b=x+20+15+8, c=x+20+15+8
161=3x+40+40+35+24
27=3x, x=9%*1000=90

ans (E)
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In a survey it was found that 10% people don’t use Facebook, Twitter 28 Apr 2020, 21:48
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In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsap. 8% uses all the three. There are 15% who uses only Facebook and Twitter, 20% who use only Twitter and Whatsap and 20% who use only Facebook and Whatsap. Number of people that use only Facebook, only Twitter and only Whatsap are equal. If the survey was conducted on 1000 people, how many people use Whatsap only?

A. 9
B. 15
C. 20
D. 45
E. 90
total=3(only one)+exactly 2 of them+three+neither
1000=3a+630+100
on solving,
only one=90
Ans E
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In a survey it was found that 10% people don’t use Facebook, Twitter Updated on: 29 Apr 2020, 07:20
Originally posted by Staphyk on 28 Apr 2020, 22:44.
Last edited by Staphyk on 29 Apr 2020, 07:20, edited 3 times in total.
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Lolx don’t know where from this “https: something “ tryna edit it but ain’t working. Hope you guys can still follow the solution
All social media users = 1000
All three =80
Neither users = 100
Facebook and Twitter only = 150
Twitter and WhatsApp only = 200
Facebook and WhatsApp only = 200

Facebook ,Twitter ,WhatsApp only = x
WhatsApp only = ?

1000= F + T +W -(FnT+TnW+WnF)+ all three +Neither

1000= (x+200+80+150)+(x+150+80+200)+(x+200+80+200)-(230+280+280) +80 +100

1000= 3x +430+430+480 - (790) +80+100
1000= 3x + 1340 -790 +180
270 =3x ,x =90

.: WhatsApp only = 90

E for epidemic

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In a survey it was found that 10% people don’t use Facebook, Twitter 28 Apr 2020, 23:16
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let x be the no.of people who use only facebook, only watsapp, only twitter each.

from above given info we can write as below

1000= x+x+x+150+200+200+80+100
3x=100-730=270
x=90

OA:E
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In a survey it was found that 10% people don’t use Facebook, Twitter 29 Apr 2020, 07:04
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In the overlapping sets you're supposed to subtract (150+200+200)

WHy have you used a plus sign?

madgmat2019
let x be the no.of people who use only facebook, only watsapp, only twitter each.

from above given info we can write as below

1000= x+x+x+150+200+200+80+100
3x=100-730=270
x=90

OA:E
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In a survey it was found that 10% people don’t use Facebook, Twitter 29 Apr 2020, 07:05
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Bunuel

Competition Mode Question



In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsap. 8% uses all the three. There are 15% who uses only Facebook and Twitter, 20% who use only Twitter and Whatsap and 20% who use only Facebook and Whatsap. Number of people that use only Facebook, only Twitter and only Whatsap are equal. If the survey was conducted on 1000 people, how many people use Whatsap only?

A. 9
B. 15
C. 20
D. 45
E. 90


Are You Up For the Challenge: 700 Level Questions
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Given:
1. In a survey it was found that 10% people don’t use Facebook, Twitter or Whatsap.
2. 8% uses all the three.
3. There are 15% who uses only Facebook and Twitter, 20% who use only Twitter and Whatsap and 20% who use only Facebook and Whatsap.
4. Number of people that use only Facebook, only Twitter and only Whatsap are equal.

Asked: If the survey was conducted on 1000 people, how many people use Whatsap only?

Attachment:
Screenshot 2020-04-28 at 4.25.08 PM.png
Screenshot 2020-04-28 at 4.25.08 PM.png [ 45.62 KiB | Viewed 13496 times ]

3x% + 73% = 100%; x% = 9%
The number of people that uses Whatsap only = 9%*1000 = 90

IMO E
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In a survey it was found that 10% people don’t use Facebook, Twitter 12 Jun 2025, 06:29
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