If Carlos wants to buy 2,000 balloons, how much money does he save by buying 1,000 balloons at a time rather than ten balloons at a time?

Balloons are sold according to the chart above. If a customer buys one balloon at a time, the cost is $1.00 per balloon. If a customer buys ten balloons at a time, the cost is $0.90 per balloon.

If Carlos wants to buy 2,000 balloons, how much money does he save by buying 1,000 balloons at a time rather than ten balloons at a time?
A . $200
B . $300
C . $500
D . $600
E . $800

Answer: D

Explanation:

If Carlos buys ten balloons, he will pay 10 × $0.90 = $9. In order to total 2,000 balloons, Carlos will have to make this purchase 2,000 ÷ 10 = 200 times. It will cost him a total of 200 × $9 = $1,800. If Carlos buys 1,000 balloons, he will pay 1,000 × $0.60) = $600. In order to total 2,000 balloons, Carlos will have to make this purchase 2,000 ÷ 1,000 = 2 times. It will cost him a total of 2 × $600 = $1,200. It will save Carlos $1,800 C $1,200 = $600 to buy the balloons 1,000 at a time.