Calculate Black Chairs: Finding 40 Percent of 125 Using Complementary Percentages

To solve this problem, we'll follow these steps:

• Step 1: Calculate the number of white chairs from the given percentage.
• Step 2: Determine the number of black chairs by subtraction.

Let's work through each step:

Step 1: Calculate the number of white chairs.
The total number of chairs is 125. Since 60% of these chairs are white, we calculate the number of white chairs as follows:
$\text{White chairs} = 125 \times 0.60 = 75$

Step 2: Determine the number of black chairs.
Subtract the number of white chairs from the total number of chairs to find the number of black chairs:
$\text{Black chairs} = 125 - 75 = 50$

Therefore, the number of black chairs is 50.