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Main Question or Discussion Point
I would just like someone to check maths for this venn diagram, just to make sure I have done the calculations correct. I have attached copy, with the numbering inside the diagram. I will show my working here.
Question: One of 36 tourists on holiday in Namibia and South Africa is chosen at random.
The probability that he has been to south africa before is 1/2
The probability that he has been to Namibia before is 4/9
The probability that he has been to neither country before is 1/3
So here is how I worked it out: I convert all the fractions to percentages and add them together:
1/2 = 0.50 = 50%
4/9 = 0.44444 = 44.4%
1/3 = 0.33333 = 33.3%
I the add the fraction or percentages up which gave me: 127.777777778.
I then did 36/100 = 0.36*127.777777778, which gave me 46.0000000001; I rounded this number to 46.
I then took 4636 = 10, this gave me the intersection of the two circles.
Once I had done this, I took 1/2 of 36, 4/9 of 36, which respectively gave me 16 and 18.
So I then went on and did 1610=6 so 8 people went to Namibia, 1810 = 8 people went to south Africa. This gives me a grand total of 24. I then did 3624 = 12 people which have not been to either. I did double check with the 1/3 of 36 which is correct.
I would appreciate if someone could take a look just to make sure this is correct method.
Question: One of 36 tourists on holiday in Namibia and South Africa is chosen at random.
The probability that he has been to south africa before is 1/2
The probability that he has been to Namibia before is 4/9
The probability that he has been to neither country before is 1/3
So here is how I worked it out: I convert all the fractions to percentages and add them together:
1/2 = 0.50 = 50%
4/9 = 0.44444 = 44.4%
1/3 = 0.33333 = 33.3%
I the add the fraction or percentages up which gave me: 127.777777778.
I then did 36/100 = 0.36*127.777777778, which gave me 46.0000000001; I rounded this number to 46.
I then took 4636 = 10, this gave me the intersection of the two circles.
Once I had done this, I took 1/2 of 36, 4/9 of 36, which respectively gave me 16 and 18.
So I then went on and did 1610=6 so 8 people went to Namibia, 1810 = 8 people went to south Africa. This gives me a grand total of 24. I then did 3624 = 12 people which have not been to either. I did double check with the 1/3 of 36 which is correct.
I would appreciate if someone could take a look just to make sure this is correct method.
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