document.write( "Question 1201973: In survey of 900 workers 600 owned houses,500 owned cars and 345 owned boat,300 owned cars and houses,250 owned houses and boats and 270 owned cars and boats 200 owned the three.find how many workers don't owned any of items, find how many workers owned only two of the items \n" ); document.write( "
Algebra.Com's Answer #836581 by math_tutor2020(3816)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Set H = houses \n" ); document.write( "Set C = cars \n" ); document.write( "Set B = boats\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's draw out a venn diagram \n" ); document.write( "The uppercase letters represent the circle names/labels \n" ); document.write( "The lowercase letters are the 8 regions I'll talk about down below. \n" ); document.write( " \n" ); document.write( "There are 8 distinct regions
\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We have these given facts \n" ); document.write( "
\n" ); document.write( "Fact 8 is where we'll start. \n" ); document.write( "This tells us that 200 goes in region e at the very center. \n" ); document.write( "It's where all three circles overlap.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We'll then use Fact 7 and Fact 8 to determine there must be 270-200 = 70 people who own a car and a boat, but not a house. \n" ); document.write( "The value 70 goes inside region f.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next use Fact 6 and Fact 8 together to determine there are 250-200 = 50 people who own a house and a boat, but no car. \n" ); document.write( "The value 50 goes in region d.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next up will be Fact 5 and Fact 8 used together. We can say there are 300-200 = 100 people who own a house and a car, but no boat. \n" ); document.write( "The value 100 goes in region b.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here's what we have so far \n" ); document.write( "b = 100 \n" ); document.write( "d = 50 \n" ); document.write( "e = 200 \n" ); document.write( "f = 70 \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Focus your attention on circle H. \n" ); document.write( "The values in this circle must add to 600 (due to Fact 2) \n" ); document.write( "That means... \n" ); document.write( "a+b+d+e = 600 \n" ); document.write( "a+100+50+200 = 600 \n" ); document.write( "a+350 = 600 \n" ); document.write( "a = 600-350 \n" ); document.write( "a = 250 \n" ); document.write( "There are 250 people who own a house, but not a car and also not a boat.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now move your attention to circle C. \n" ); document.write( "We use Fact 3 to say the following: \n" ); document.write( "b+c+e+f = 500 \n" ); document.write( "100+c+200+70 = 500 \n" ); document.write( "c+370 = 500 \n" ); document.write( "c = 500-370 \n" ); document.write( "c = 130\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use a similar idea for circle B. Refer to Fact 4 \n" ); document.write( "d+e+f+g = 345 \n" ); document.write( "50+200+70+g = 345 \n" ); document.write( "320+g = 345 \n" ); document.write( "g = 345-320 \n" ); document.write( "g = 25\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We have these values \n" ); document.write( "a = 250, b = 100, c = 130 \n" ); document.write( "d = 50, e = 200, f = 70 \n" ); document.write( "g = 25 \n" ); document.write( "which leads to this nearly completed venn diagram \n" ); document.write( " \n" ); document.write( "The last thing to figure out is what we put in region h.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's add up all of the values in the circles ('a' through 'g') \n" ); document.write( "a+b+c+d+e+f+g = 250+100+130+50+200+70+25 = 825\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "This represents the total number of people who have at least one (i.e. one or more) item mentioned.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then we use Fact 1 to determine how many people have none of those three items \n" ); document.write( "900-825 = 75 \n" ); document.write( "There are 75 people who own neither a house, nor a car, nor a boat. \n" ); document.write( "This value goes in region h.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here's the completed venn diagram \n" ); document.write( " \n" ); document.write( "where, \n" ); document.write( "a = 250, b = 100, c = 130 \n" ); document.write( "d = 50, e = 200, f = 70 \n" ); document.write( "g = 25, h = 75\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now onto the questions:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question 1) how many workers don't own any of those items? \n" ); document.write( "Answer: 75 \n" ); document.write( "Reason: See region h of the venn diagram\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question 2) how many workers own only two of the items? \n" ); document.write( "Answer: 220 \n" ); document.write( "Reason: b+d+f = 100+50+70 = 220 \n" ); document.write( "Ignore region e because that subset of people own all 3 items. \n" ); document.write( " \n" ); document.write( " |