I am trying to do these questions by employing the Double MAtrix Charts. I do not want THE VENN DIAGRAM WAY. ANy help?
- Attachments
-
-
Appetite for 700 and I scraped my plate!
The first one is not that straight forward, but is much easier to view when you break down the information.
You can draw a chart with R NR for Russian, No Russian and F NF for French, no French.
The intersection of F and R will be your .10 figure (10 percent)
The intercection of NR and NF will be your .20 figure.
Then, you enter x for the total.
Now, you are told that 32 DO NOT speak Russian, so let's put that number in the total for NR.
You are also told that 20 speak French. So, enter 20 for the total of F.
Now, you can plug in a number for x, and it is better to start with a nice number like 120 or 150. I would usually start with 120, which would then show me whether I should work up or down, but I will start with 150, to prove my point.
150 - 20 = 130 total for people who do not speak French.
.20(150) = 30 who speak nether language, which leaves you with 2 who speak French but no Russian and 18 who speak both.
Now, is 10 percent of 150 = 18? No.
So, try the same thing with 120, now.
120 - 20 = 100 who speak no French at all.
.20(120) = 24 who speak neither Russian nor French, which leaves you with 8 who speak French but no Russian and 12 who Speak both.
Is 12 10 percent of 120? YES!
That is your answer.
This problem took me a little over 2 minutes to solve. I am sure that there is a faster way, but this is how I would solve it on the exam.
