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

Answer

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

### Step-by-Step Solution:

1. **Understand the Ratio**:
- The ratio of Cost Price (CP) to Selling Price (SP) is given as 5:4. This means if we let the Cost Price be 5x, then the Selling Price will be 4x for some value of x.

2. **Express CP and SP**:
- Let CP = 5x
- Let SP = 4x

3. **Calculate the Loss**:
- Loss = Cost Price - Selling Price
- Loss = CP - SP = 5x - 4x = x

4. **Calculate the Loss Percentage**:
- Loss Percent = (Loss / Cost Price) × 100
- Loss Percent = (x / 5x) × 100

5. **Simplify the Expression**:
- Loss Percent = (1/5) × 100 = 20%

### Final Answer:
The loss percent is **20%**.

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