I'm completely lost with this math problem: Grace is looking to plant some lettuce in her raised bed garden. Her raised bed is comprised of 2 large beds on top with 2 medium beds on the bottom. The top bed can hold 4 rows of lettuce with 25 seeds being sown per row. The medium bed can house 3 rows with 20 seeds being sown per row. How many seeds can Grace plant in all four beds of her raised bed garden?
Can you give me a hand?