Answer:
She will need 40 candles to make 100 dollars
Explanation:
Step 1: Determine price per unit of candle
The price per unit of candle can be expressed as;
Price per unit=Total cost of candles/Number of candles sold
where;
Total cost of candles=10 dollars
Number of candles sold=4
replacing;
Price per unit=10/4=2.50 dollars
This means that 1 candle will be sold for 2.50 dollars
Step 2: Number of candles needed to make 100 dollars
Number of candles sold=Total cost of candles/Price per unit
where;
Total cost of candles=100 dollars
Price per unit=2.5 dollars per candle
replacing;
Number of candles sold=(100/2.5)=40
She will need 40 candles to make 100 dollars