Find out how many people have visited 38 pupil were asked if they are visited Thailand,Brunei or Indonesia before. 4 of them have been to all three counties, 8 have been to Thailand &...

Find out how many people have visited 

38 pupil were asked if they are visited Thailand,Brunei or Indonesia before. 4 of them have been to all three counties, 8 have been to Thailand & Bruneu,15 been brunei & Indonesia,& 11 of them been Thailand and Indonesia. Given 18 had been to Thailand, 19 Brunei & 26 Indonesia. Find out,How many people have visited

A) One of the three countries only

B)More than one of the three countries.

Asked on by piqachu

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jeew-m's profile pic

jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted on

This question is based on sets.

Let;

T = set of pupil who has been to thailand

B = set of pupil who has been to Brunei

I = set of pupil who has been to Indonesia

 

According to the data

`n(T nn B nn I) = 4`

`n(T nn B) = 8-4 = 4`

`n(T nn I) =11-4 = 7`

`n(I nn B) = 15-4 = 11 `

 

It is given that;

n(T) = 18

n(B) =19

n(I ) =26

 

Pupil only have been to Thailand

= `18-n(T nn B)-n(T nn I)-n(T nn B nn I)`

= 18-4-7-4

= 3

 

Pupil only have been to Brunei

= `19-n(T nn B)-n(B nn I)-n(T nn B nn I)`

= 19-4-11-4

= 0

 

Pupil only have been to Indonesia

= `26-n(I nn B)-n(T nn I)-n(T nn B nn I)`

= 26-11-7-4

= 4

 

A)

Number of people that visited one country only = 4+3 = 7

 

B)

Number of people that visited more than one country

 = total people - Number of people visited one country only

 = (18+19+26) - 7

 = 56

 

Sources:

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