Question: A farmer owns a hog that recently gave birth to 6 piglets. If the farmer raises the piglets until they are fully grown, he can sell the fully grown pig for $300. Each piglet must grow for at least 12 months before it is large enough to be sold. It costs the farmer $10 per month to feed each animal until it is sold. If the farmer sells 3 pigs after 12 months, and the remaining 3 pigs after 16 months, how much profit did he earn in total (after deducting the cost of food)? Think carefully first, then make a decision:
The 3 pigs that are sold after 12 months will cost the farmer 12 * 10 * 3 = $360 in food costs. The 3 pigs that are sold after 16 months will cost the farmer 16 * 10 * 3 = $480 in food costs. Thus, the total food cost to raise the 6 piglets was 360 + 480 = $840. Next, selling the 6 fully grown pigs will earn the farmer 6 * 300 = $1800 in revenue. Therefore, the earn the farmer 1800 - 840 = $960 in profit from these sales. So the answer is 960.