Lizzy: A hay farmer harvested 560 bales of hay from 5 acres of grass per month last year. This year, he planted an additional 7 acres of grass. If the farmer also owns 9 horses and each horse consumes 3 bales of hay a day, how many bales of hay would the farmer have left by the end of December if he starts feeding them this year's hay beginning the first day of September?.
Me: Hmmm, let me think. I think this is the detailed solution:
For every acre of grass, the farmer can harvest 560 / 5 = 112 bales of hay each month. This year, the farmer has 7 + 5 = 12 acres of grass. He can expect to harvest 12 x 112 = 1344 bales of hay per month. The total hay production this year is 1344 * 12 = 16128. From September to December, the farmer would have to feed his horses for a total of 30 + 31 + 30 + 31 = 122 days. Each day his horse eats a total of 3 * 9 = 27 bales of hay. For the 122 days, the horses will eat a total of 27 * 122 = 3294 bales. The total number of bales remaining will be 16128 - 3294 = 12834. Final answer: 12834.