Answer:
Becky saves $4.86 by choosing to buy 18 bulbs in the 3 package sets
Step-by-step explanation:
Becky has 2 options here. She can buy 3 for $4.20 or 2 for $3.34. We can easily determine the prices because both 2 & 3 are factors of 18.
18 / 3 = 6, so multiply 6 * 4.20 to see that 18 bulbs will cost $25.20
18 / 2 = 9, so multiply 9 * 3.34 to see that 18 bulbs will cost $30.06
Now, we can see that buying sets of 3 is cheaper, we need to determine how much we are saving by choosing the cheaper option. (Use subtraction)
$30.06 - $25.20 = $4.86
Becky saves $4.86 by choosing to buy 18 bulbs in the 3 package sets
