To determine the cost per candle, we can set up an equation based on the information given:
- Kayla is purchasing 5 candles, each costing \( x \) dollars.
- She is also purchasing 5 candle holders, each costing $3.50.
The total amount paid is $27.50. We can express this mathematically:
\[ 5x + 5(3.50) = 27.50 \]
Next, we calculate the total cost of the candle holders:
\[ 5(3.50) = 17.50 \]
Now we can substitute this value back into the equation:
\[ 5x + 17.50 = 27.50 \]
To isolate \( 5x \), we subtract 17.50 from both sides:
\[ 5x = 27.50 - 17.50 \] \[ 5x = 10.00 \]
Now, divide both sides by 5 to solve for \( x \):
\[ x = \frac{10.00}{5} = 2.00 \]
Thus, the cost per candle is \( \boxed{2.00} \).