The ratio of cost price and selling price is 4 : 5, the profit percent is :

Answer

To find the profit percentage when the ratio of cost price (CP) to selling price (SP) is given as 4:5, we can follow these steps:

### Step 1: Define the Cost Price and Selling Price
Given the ratio of CP to SP is 4:5, we can express them in terms of a common variable \( k \):
- Cost Price (CP) = \( 4k \)
- Selling Price (SP) = \( 5k \)

### Step 2: Calculate the Profit
Profit is calculated as the difference between Selling Price and Cost Price:
\[ \text{Profit} = \text{SP} - \text{CP} = 5k - 4k = k \]

### Step 3: Calculate the Profit Percentage
Profit percentage is calculated using the formula:
\[ \text{Profit Percentage} = \left( \frac{\text{Profit}}{\text{CP}} \right) \times 100 \]
Substituting the values we have:
\[ \text{Profit Percentage} = \left( \frac{k}{4k} \right) \times 100 \]

### Step 4: Simplify the Expression
Now, simplify the expression:
\[ \text{Profit Percentage} = \left( \frac{1}{4} \right) \times 100 = 25\% \]

### Final Answer
The profit percentage is **25%**.

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