document.write( "Question 1208266: Good day. please help me solve this problems.
\n" ); document.write( "Consider a bag containing 5 blue marbles and 3 green marbles.\r
\n" ); document.write( "\n" ); document.write( "I. Construct a tree diagram to represent all possible outcomes of drawing two marbles when the marble is replaced after each draw. [4 marks]\r
\n" ); document.write( "\n" ); document.write( "II. What is the probability of drawing two blue marbles in a row? [2 marks]\r
\n" ); document.write( "\n" ); document.write( "III. What is the probability of selecting a colour of each? [2 marks]
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\n" ); document.write( "IV. Construct a tree diagram to represent all possible outcomes of drawing two marbles without replacement. [4 marks]
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Algebra.Com's Answer #846578 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Part I\r
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\n" ); document.write( "\n" ); document.write( "This is one way to draw the probability tree diagram.
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\n" ); document.write( "This style has it flow from left to right.
\n" ); document.write( "Another diagram style would have it flow from top to bottom (rotate the diagram shown above 90 degrees clockwise).\r
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\n" ); document.write( "\n" ); document.write( "The probability tree should be self-explanatory.
\n" ); document.write( "Perhaps the only explanation that's needed is each item in the \"outcome\" column is the result of multiplying the fractions along the particular pathway.\r
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\n" ); document.write( "\n" ); document.write( "For instance, multiply the fractions along the upper most path to get (5/8)*(5/8) = 25/64 which is the probability of selecting 2 blue marbles in a row where replacement is done.\r
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\n" ); document.write( "\n" ); document.write( "The list of possible outcomes are
\n" ); document.write( "P(BB) = 25/64
\n" ); document.write( "P(BG) = 15/64
\n" ); document.write( "P(GB) = 15/64
\n" ); document.write( "P(GG) = 9/64\r
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\n" ); document.write( "\n" ); document.write( "Optionally we can make a table of outcomes
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2nd is B2nd is G
1st is B25/6415/64
1st is G15/649/64
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\n" ); document.write( "\n" ); document.write( "Note that P(BB)+P(BG)+P(GB)+P(GG) = (25/64)+(15/64)+(15/64)+(9/64) = 1\r
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\n" ); document.write( "\n" ); document.write( "More Practice
\n" ); document.write( "https://www.mathsisfun.com/data/probability-tree-diagrams.html\r
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\n" ); document.write( "\n" ); document.write( "Part II\r
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\n" ); document.write( "\n" ); document.write( "I'll assume replacement is applied.
\n" ); document.write( "P(BB) = probability of two blue marbles in a row with replacement
\n" ); document.write( "P(BB) = 25/64 was calculated back in part I. \r
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\n" ); document.write( "\n" ); document.write( "Highlight the upper most path for the two blue marbles.
\n" ); document.write( "Multiply the fractions along this path.\r
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\n" ); document.write( "\n" ); document.write( "Part III\r
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\n" ); document.write( "\n" ); document.write( "I'll assume replacement is applied.\r
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\n" ); document.write( "\n" ); document.write( "There are two methods we could use.
\n" ); document.write( "The first method is most direct and quickest.
\n" ); document.write( "P(one of each color) = P(BG) + P(GB)
\n" ); document.write( "P(one of each color) = (15/64)+(15/64)
\n" ); document.write( "P(one of each color) = (15+15)/64
\n" ); document.write( "P(one of each color) = 30/64
\n" ); document.write( "P(one of each color) = (2*15)/(2*32)
\n" ); document.write( "P(one of each color) = 15/32\r
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\n" ); document.write( "\n" ); document.write( "Here is another approach.
\n" ); document.write( "P(two of same color) = P(2 blue OR 2 green)
\n" ); document.write( "P(two of same color) = P(BB)+P(GG)
\n" ); document.write( "P(two of same color) = (25/64)+(9/64)
\n" ); document.write( "P(two of same color) = (25+9)/64
\n" ); document.write( "P(two of same color) = 34/64
\n" ); document.write( "P(two of same color) = (2*17)/(2*32)
\n" ); document.write( "P(two of same color) = 17/32
\n" ); document.write( "Then,
\n" ); document.write( "P(one of each color) = 1 - P(two of same color)
\n" ); document.write( "P(one of each color) = 1 - (17/32)
\n" ); document.write( "P(one of each color) = (32/32) - (17/32)
\n" ); document.write( "P(one of each color) = (32-17)/32
\n" ); document.write( "P(one of each color) = 15/32\r
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\n" ); document.write( "\n" ); document.write( "Part IV\r
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\n" ); document.write( "\n" ); document.write( "This probability tree is very similar to the tree in part I.
\n" ); document.write( "The 5/8 and 3/8 in the 1st column, or left-most column, are the same as before.\r
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\n" ); document.write( "\n" ); document.write( "The fractions in the 2nd column are new. The 7s in the denominator refer to the number of marbles remaining after the 1st selection is not replaced.
\n" ); document.write( "Subtract 1 from the numerator only when you are selecting two of the same color.\r
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\n" ); document.write( "\n" ); document.write( "To get each item in the \"outcome\" column, you follow the same idea as mentioned earlier.
\n" ); document.write( "Example: Multiplying along the top most pathway yields (5/8)*(4/7) = 20/56 = 5/14 which is the probability of getting two blue marbles in a row when replacement is not applied.
\n" ); document.write( "Use this idea for the other three pathways.\r
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\n" ); document.write( "\n" ); document.write( "Here is an optional table of outcomes
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2nd is B2nd is G
1st is B5/1415/56
1st is G15/563/28

\n" ); document.write( "Or we can list them out like so
\n" ); document.write( "P(BB) = 5/14
\n" ); document.write( "P(BG) = 15/56
\n" ); document.write( "P(GB) = 15/56
\n" ); document.write( "P(GG) = 3/28\r
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\n" ); document.write( "\n" ); document.write( "Note that P(BB)+P(BG)+P(GB)+P(GG) = (5/14)+(15/56)+(15/56)+(3/28) = 1\r
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\n" ); document.write( "\n" ); document.write( "Summary of answers:
  1. Diagram is shown above.
  2. probability of two blue in a row = 25/64 (with replacement)
  3. probability one of each color = 15/32 (with replacement)
  4. Diagram is shown above.

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