When the price of a TV was increased by `15%` the number of TV’s sold by a company decreases by `15%`. What was the net effect on the sale?

Options

A. No effect
B. `1 cdot 5%` increase
C. `2 cdot 25%` decrease
D. `2 cdot 25%` increase

Answer

To solve the problem, we need to determine the net effect on sales when the price of a TV is increased by 15% and the quantity sold decreases by 15%. We will use the formula for calculating the net effect on sales when both price and quantity change.

### Step-by-Step Solution:

1. **Identify the Changes**:
- Price increase = 15% (denote this as x)
- Quantity decrease = 15% (denote this as y)

2. **Use the Formula**:
The formula to calculate the net effect on sales when there is a price increase and a quantity decrease is:
\[ \text{Net Effect} = x + y - \frac{xy}{100} \]

3. **Substitute the Values**:
Substitute x and y into the formula:
\[ \text{Net Effect} = 15 + (-15) - \frac{15 \times (-15)}{100} \]

4. **Calculate Each Component**:
- First, calculate \(x + y\):
\[ 15 - 15 = 0 \]
- Next, calculate \(\frac{xy}{100}\):
\[ \frac{15 \times 15}{100} = \frac{225}{100} = 2.25 \]

5. **Combine the Results**:
Now, substitute back into the net effect formula:
\[ \text{Net Effect} = 0 + 2.25 = 2.25 \]

6. **Determine the Sign**:
Since the price increased and the quantity decreased, the net effect is an increase in sales. Therefore, the final result is:
\[ \text{Net Effect on Sale} = 2.25\% \text{ increase} \]

### Final Answer:
The net effect on the sale is a **2.25% increase**.