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December 3rd, 2011, 12:34 AM   #1
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Sets helps....

In a survey of 120 people,
48 Played basketball ,
78 Played Soccer,
66 Played Volleyball,
36 Played any given pair of these sports ,
24 Played them all.
Find the number of the people that played at least one of the sports..
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December 3rd, 2011, 12:44 PM   #2
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Re: Sets helps....

Set up a Venn diagram.
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December 3rd, 2011, 03:32 PM   #3
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Re: Sets helps....

venn diagram is no problem for me...but i still cnt find the actual answer...
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December 3rd, 2011, 04:37 PM   #4
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Re: Sets helps....

Let:

a = # that play basketball only
b = # that play soccer only
c = # that play volleyball only
x = # that play basketball and soccer
y = # that play basketball and volleyball
z = # that play soccer and volleyball

We are told:

x + y + z = 36
a + x + y + 24 = 48
b + x + z + 24 = 78
c + y + z + 24 = 66

Adding, we find:

(a + b + c) + 3(x + y + z + 24) = 228

(a + b + c) + (x + y + z + 24) = 228 - 2(x + y + z + 24)

(a + b + c) + (x + y + z) + 24 = 228 - 2(36 + 24) = 108

This expression represents the number of people who play at least one of the given sports.
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December 3rd, 2011, 05:17 PM   #5
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Re: Sets helps....

Hello, dannyboyz!

Quote:
In a survey of 120 people:
[color=beige]. . [/color]48 played Basketball.
[color=beige]. . [/color]78 played Soccer.
[color=beige]. . [/color]66 played Volleyball.
[color=beige]. . [/color]36 played Basketball and Soccer.
[color=beige]. . [/color]36 played Soccer and Volleyball.
[color=beige]. . [/color]36 played Basketball and Volleyball.
[color=beige]. . [/color]24 played all three sports.

Find the number of the people that played at least one of the sports.

Are you familiar with this formula?



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December 4th, 2011, 05:15 AM   #6
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Re: Sets helps....

thx for the reply..i also find that the answer is 108...

I am confuse tat why my tutor say the answer is wrong ==
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December 4th, 2011, 09:06 AM   #7
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Re: Sets helps....

How does your tutor work the problem?
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December 4th, 2011, 11:07 PM   #8
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Re: Sets helps....

Today i go and ask my tutor again..she said...the answer is not wrong ==
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