Set Theory: In a class of 48 students, 22 offered Physics, 20 offered Agricultural science, 18 offered Literature.

Safha

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In a class of 48 students, 22 offered Physics, 20 offered Agricultural science, 18 offered Literature. 3 students offered both Literature and Agricultural science, 4 students offered both Physics and Agricultural Science. Find the number of students that take all the three subjects, If 5 students take non of the subjects.
 

pka

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In a class of 48 students, 22 offered Physics, 20 offered Agricultural science, 18 offered Literature. 3 students offered both Literature and Agricultural science, 4 students offered both Physics and Agricultural Science. Find the number of students that take all the three subjects, If 5 students take non of the subjects.
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Inside the there are a total of 48 students, so \(\displaystyle j+k+m+x+y+z+w+5=48\).
Now we are looking for z the number that take all three subjects.
The given tells us that \(\displaystyle j+x+w+z=22\) because twenty-two take physics.
\(\displaystyle x+w=4\) because four take both physics & agriculture.
You must proceed to establish all equations necessary to find the value of each variable.
Please post your results.
 

pka

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This is a correction Now we are looking for \(\displaystyle \large \color{red}w\), the number that take all three subjects.
 

Dr.Peterson

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I see 6 equations for 7 variables. I don't see that we can solve for w. I may be missing something. But is it possible something was omitted from the problem?
 

pka

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I see 6 equations for 7 variables. I don't see that we can solve for w. I may be missing something. But is it possible something was omitted from the problem?
Well I admit I make a stupid mistake in subtraction. Now I see that some bit of information is missing.
If only I knew how many students take only Agricultural science then there is a unique solution.
 
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