document.write( "Question 1204589: In a recent survey of 180 housewives. The following were determined with regard to their detergent soap preferences\r
\n" ); document.write( "\n" ); document.write( "65 use brand A
\n" ); document.write( "140 use brand B
\n" ); document.write( "145 use brand C
\n" ); document.write( "115 use B and C
\n" ); document.write( "23 use A but not B
\n" ); document.write( "12 use A but not C
\n" ); document.write( "18 use A and C but not B\r
\n" ); document.write( "\n" ); document.write( "A) Draw a Venn diagram to summarize the given data.
\n" ); document.write( "B) Determine the number of housewives who use all 3 soaps.
\n" ); document.write( "C) How many do not use any of the above brands.
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Algebra.Com's Answer #840949 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Here's a template of a venn diagram with 3 circles that partially overlap.
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\n" ); document.write( "The goal is to place a number into each of the 8 separate regions.\r
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\n" ); document.write( "\n" ); document.write( "18 people use A and C, but not B. This means we'll place 18 in circles A and C, but outside circle B as shown below
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\n" ); document.write( "23 housewives use brand A but not brand B
\n" ); document.write( "This must mean the value in circle A outside the other circles must be 5, since 5+18 = 23. Or you could think of it like 23-18 = 5.
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\n" ); document.write( "12 use brand A but not brand C.
\n" ); document.write( "We already have 5 people who use brand A exclusively, so the remaining 12-5 = 7 people must use brand A but not brand C.\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "At this point, we almost have all of the regions pertaining to circle A. The missing part is where all 3 circles overlap.\r
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\n" ); document.write( "\n" ); document.write( "The values so far in circle A are: 5, 7, 18
\n" ); document.write( "They add to 5+7+18 = 30
\n" ); document.write( "There are 30 housewives so far that use brand A (and some use other brands as well).
\n" ); document.write( "The instructions state that 65 women use brand A, so 65-30 = 35 must use all three brands.\r
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\n" ); document.write( "\n" ); document.write( "We'll place this value in the overlapped portion of all 3 circles.
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\n" ); document.write( "Circle A is completely filled out.\r
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\n" ); document.write( "\n" ); document.write( "Next, we're told that \"115 use B and C\"
\n" ); document.write( "So the numbers in the overlapped region of circles B and C must add to 115
\n" ); document.write( "There are already 35 who use all three brands, so 115-35 = 80 use brand B and brand C, but not brand A.
\n" ); document.write( "Let's update the venn diagram\r
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\n" ); document.write( "\n" ); document.write( "Circle B is almost complete.
\n" ); document.write( "The values in this circle add to: 7+35+80 = 122
\n" ); document.write( "And there are 140 who use brand B, which tells us there are 140-122 = 18 people who use brand B only.
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\n" ); document.write( "We're done with Circle B.\r
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\n" ); document.write( "\n" ); document.write( "Now onto circle C.
\n" ); document.write( "The values add to 18+35+80 = 133
\n" ); document.write( "There are 145 people who use brand C, so the remaining 145-133 = 12 housewives use brand C exclusively.
\n" ); document.write( "Let's update the venn diagram.\r
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\n" ); document.write( "All of the circles are now completely filled in.\r
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\n" ); document.write( "\n" ); document.write( "The missing number is what goes outside the three circles. This represents the subset of women who don't use any of the three brands mentioned.\r
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\n" ); document.write( "\n" ); document.write( "Let's add up all of the values inside those circles.
\n" ); document.write( "5+7+18+18+35+80+12 = 175\r
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\n" ); document.write( "\n" ); document.write( "There are 175 housewives who use one or more of brand A,B, and/or C.
\n" ); document.write( "This is out of the 180 housewives surveyed.
\n" ); document.write( "Therefore, there must be 180-175 = 5 housewives who don't use any of the 3 brands.
\n" ); document.write( "We place this new value outside of the circles.\r
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\n" ); document.write( "The venn diagram is complete.\r
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\n" ); document.write( "\n" ); document.write( "You can use this venn diagram to answer parts (b) and (c).
\n" ); document.write( "I'll let the student take over from here.\r
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\n" ); document.write( "\n" ); document.write( "More practice with venn diagrams (that have 3 circles)
\n" ); document.write( "https://www.algebra.com/algebra/homework/Subset/Subset.faq.question.1196992.html
\n" ); document.write( "and
\n" ); document.write( "https://www.algebra.com/algebra/homework/Finance/Finance.faq.question.1201924.html
\n" ); document.write( "and
\n" ); document.write( "https://www.algebra.com/algebra/homework/sets-and-operations/sets-and-operations.faq.question.1199899.html
\n" ); document.write( "and
\n" ); document.write( "https://www.algebra.com/algebra/homework/Subset/Subset.faq.question.1192015.html
\n" ); document.write( "I also recommend searching out for other examples on YouTube so you can see how the venn diagram is filled out in a step-by-step process.
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