A school has only four classes that contain 10,20,30 and 40 students respectively. The pass percentage of these classes are 20%, 30%, 60% and 100% respectively. Find the pass % of the entire school.

Options

A. `56%`
B. ` 76%`
C. `34%`
D. `66%`

Answer

To find the overall pass percentage of the school, we need to calculate the total number of students and the total number of students who passed from each class.

### Step-by-Step Solution:

1. **Calculate Total Students in Each Class:**
- Class 1: 10 students
- Class 2: 20 students
- Class 3: 30 students
- Class 4: 40 students

**Total Students = 10 + 20 + 30 + 40 = 100 students**

2. **Calculate the Number of Students Who Passed in Each Class:**
- Class 1: 20% of 10 students = \( \frac{20}{100} \times 10 = 2 \) students passed
- Class 2: 30% of 20 students = \( \frac{30}{100} \times 20 = 6 \) students passed
- Class 3: 60% of 30 students = \( \frac{60}{100} \times 30 = 18 \) students passed
- Class 4: 100% of 40 students = \( \frac{100}{100} \times 40 = 40 \) students passed

3. **Calculate Total Students Who Passed:**
**Total Passed = 2 + 6 + 18 + 40 = 66 students passed**

4. **Calculate the Overall Pass Percentage:**
- Overall Pass Percentage = \( \frac{\text{Total Passed}}{\text{Total Students}} \times 100 \)
- Overall Pass Percentage = \( \frac{66}{100} \times 100 = 66\% \)

### Final Answer:
The overall pass percentage of the entire school is **66%**.