Remi prepared a tomato nursery and planted tomato seedlings. After 20 days, the seedlings were ready to be transferred. On the first day, he planted 200 seedlings on the farm. On the second day, while working alongside his father, he planted twice the number of seedlings he planted on the first day. If the total number of seedlings transferred to the farm on these two days was 1200, how many seedlings did his father plant? Let's think first. Chain of thought:
On the second day, he planted 2 * 200 seedlings = 400 seedlings. The total number of seedlings Remi planted on the two days is 400 seedlings + 200 seedlings = 600 seedlings. If the total number of seedlings transferred from the nursery was 1200 after the second day, Remi's father planted 1200 seedlings - 600 seedlings = 600 seedlings.
Therefore, the answer is 600.