In a test in Mathematics 20% of the students obtained first class If the data are represented by a Pie Chart, what is the central angle corresponding to "first class''?
(a)`20^(@)`
(b)`36^(@)`
(c)`72^(@)`
(d)`144^(@)`

Options

A. `20^(@)`
B. `36^(@)`
C. `72^(@)`
D. `144^(@)`

Answer

To find the central angle corresponding to the "first class" in a pie chart, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Total Percentage**:
The total percentage represented in a pie chart is 100%.

2. **Determine the Total Angle in a Pie Chart**:
The total angle in a pie chart is 360 degrees.

3. **Calculate the Angle per Percentage Point**:
To find the angle that corresponds to 1%, we divide the total angle by the total percentage:
\[ \text{Angle per 1%} = \frac{360 \text{ degrees}}{100} = 3.6 \text{ degrees} \]

4. **Calculate the Angle for 20%**:
Since 20% of the students obtained first class, we multiply the angle per 1% by 20:
\[ \text{Angle for 20%} = 20 \times 3.6 \text{ degrees} = 72 \text{ degrees} \]

5. **Conclusion**:
Therefore, the central angle corresponding to "first class" is 72 degrees.

### Final Answer:
The correct option is (c) 72 degrees.

---