In an examination, every student took Accounting or costing or both out of 600, 55% took Accounting while 72% took costing.
How many candidates took both
Let's assume the number of students who took only Accounting as A and the number of students who took only Costing as C. The number of students who took both Accounting and Costing is represented as B.
We know that:
- A + B = 55% of 600 (since 55% took Accounting)
- C + B = 72% of 600 (since 72% took Costing)
We can simplify these equations to:
- A + B = 330
- C + B = 432
We want to find the value of B, which represents the number of students who took both subjects. To do this, we need to eliminate A and C from the equations.
One way to do this is to add the two equations together:
- A + B = 330
- C + B = 432
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A + C + 2B = 762
We know that the total number of students is 600, so:
- A + B + C = 600
We can solve for A + C by subtracting B from both sides:
- A + C = 600 - B
Substituting this into the previous equation:
- A + C + 2B = 762
- (600 - B) + 2B = 762
- 600 + B = 762
- B = 162
Therefore, 162 students took both Accounting and Costing.
To find out how many candidates took both Accounting and costing, we can use the principle of inclusion-exclusion:
Let's denote:
A = candidates who took Accounting
C = candidates who took costing.
Given:
Total candidates = 600
Percentage of candidates who took Accounting = 55%
Percentage of candidates who took costing = 72%
Using this information, we can calculate the number of candidates who took Accounting as follows:
A = (55/100) * 600
A = 0.55 * 600
A = 330
Similarly, we can calculate the number of candidates who took costing as follows:
C = (72/100) * 600
C = 0.72 * 600
C = 432
Now, let's calculate the number of candidates who took both Accounting and costing:
Number of candidates who took both = A + C - Total candidates
Number of candidates who took both = 330 + 432 - 600
Number of candidates who took both = 762 - 600
Number of candidates who took both = 162
Therefore, 162 candidates took both Accounting and costing.