To solve the problem, let's denote the number of students who offer Accounting as \( A \) and the number who offer Economics as \( E \).
According to the information provided:
- The total number of students = 50.
- The number of students who offer Accounting is twice the number who offer Economics: \( A = 2E \).
- 10 students offer neither subject.
Based on this, we can find the number of students who offer at least one subject:
\[ \text{Number of students who offer at least one subject} = 50 - 10 = 40 \]
The total number of students who offer Accounting or Economics can be expressed in terms of the individual groups:
\[ A + E - X = 40 \]
where \( X \) is the number of students who offer both subjects (the intersection).
Now substituting \( A = 2E \) into the equation:
\[ 2E + E - X = 40 \] \[ 3E - X = 40 \]
Now, to find the number of students who offer only one subject, we calculate:
- Students who offer only Accounting: \( A - X \)
- Students who offer only Economics: \( E - X \)
Therefore, the formula for students who offer only one subject is:
\[ (A - X) + (E - X) = A + E - 2X \]
We also have:
\[ A + E = 3E \quad \text{(because } A = 2E\text{)} \]
Thus:
\[ 3E - 2X = \text{students who offer only one subject} \]
Now we need to express \( E \) or \( A \) in terms of \( X \) to simplify our calculations.
Let’s solve \( 3E - X = 40 \) for \( X \):
- Rearranging gives us \( X = 3E - 40 \).
- Substitute this into \( A + E - X = 40 \).
Now substitute \( X \):
\[ A + E - (3E - 40) = 40 \]
Since \( A = 2E \):
\[ 2E + E - 3E + 40 = 40 \] \[ 40 = 40 \text{ (this is true, but does not help solve for E)} \]
Now consider substituting back into \( 3E - X = 40 \):
Using trial values is practical for this kind of problem. Let’s assume values for \( E \):
Let \( E = 10 \):
Then \( A = 2E = 20 \), thus \( 20 + 10 - X = 40 \):
We already have \( X = 3E - 40\):
Setting E = 10 gives \( X = 3(10)-40 = 30-40 = -10 \) (which does not work).
Now try \( E = 15 \):
Then \( A = 2E = 30\): Using \( 30 + 15 - X = 40\):
Hence, \( 45 - X = 40 \Rightarrow X = 5\).
In this scenario:
- Students only in Accounting: \( 30 - 5 = 25\)
- Students only in Economics: \( 15 - 5 = 10\)
Thus, we have:
- Number of Students offering Accounting: 30
- Number of Students offering Economics: 15
- Students offering only one subject: \( (25 + 10 = 35) \)
Finally, the Venn diagram would show:
- Circle for Accounting: 25 (only Accounting) + 5 (both) = 30 total
- Circle for Economics: 10 (only Economics) + 5 (both) = 15 total
- Outside both circles: 10 students (neither)
Thus confirmed with the total students: \( 25 + 10 + 5 + 10 = 50\) which is correct.
Overall:
- Number of students who offer only one subject is 35.