Modern electronic shop sold the 30% hardware at the profit of 50% and 90% software at the profit of 10%. The average profit percent of the Modern electronic shop is, if it sells only these two kinds of things :

Options

A. 15
B. 20
C. 25
D. 45

Answer

To find the average profit percentage of the Modern electronic shop, we can follow these steps:

### Step 1: Identify the quantities and profit percentages
- The shop sold **30% hardware** at a **profit of 50%**.
- The shop sold **90% software** at a **profit of 10%**.

### Step 2: Convert percentages to a common scale
- For simplicity, let's assume the total sales amount is 100 units.
- Therefore, the quantities sold are:
- Hardware: 30 units
- Software: 90 units

### Step 3: Calculate the total profit from each category
- Profit from hardware:
\[ \text{Profit from hardware} = \text{Quantity of hardware} \times \text{Profit percentage of hardware} = 30 \times 50\% = 30 \times 0.5 = 15 \text{ units} \]

- Profit from software:
\[ \text{Profit from software} = \text{Quantity of software} \times \text{Profit percentage of software} = 90 \times 10\% = 90 \times 0.1 = 9 \text{ units} \]

### Step 4: Calculate the total profit
- Total profit from both hardware and software:
\[ \text{Total profit} = \text{Profit from hardware} + \text{Profit from software} = 15 + 9 = 24 \text{ units} \]

### Step 5: Calculate the total quantity sold
- Total quantity sold:
\[ \text{Total quantity} = \text{Quantity of hardware} + \text{Quantity of software} = 30 + 90 = 120 \text{ units} \]

### Step 6: Calculate the average profit percentage
- The average profit percentage can be calculated using the formula:
\[ \text{Average profit percentage} = \left( \frac{\text{Total profit}}{\text{Total quantity}} \right) \times 100 \]
Substituting the values:
\[ \text{Average profit percentage} = \left( \frac{24}{120} \right) \times 100 = 20\% \]

### Final Answer
The average profit percentage of the Modern electronic shop is **20%**.

---