Final answer:
Greg sold 200 magazine subscriptions and earns $0.50 per subscription. By multiplying the number of subscriptions (200) by the earnings per subscription ($0.50), we find that Greg earned a total of $100.
Step-by-step explanation:
Greg earns $0.50 for every magazine subscription he sells. To find out how much he earned from selling 200 magazine subscriptions, we need to multiply the number of subscriptions by the amount he earns per subscription. So, the calculation is as follows:
Amount earned per subscription = $0.50
Number of subscriptions sold = 200
Total amount earned = 200 subscriptions × $0.50 per subscription
Greg's total earnings from selling 200 magazine subscriptions would be $100. Therefore, the correct answer is (c) $100.