The ratio of Alan's apples to Don's apples was 3:5. When Alan gave 30 of his apples to Don, the ratio of Alan's apples to Don's apples became 1:5. Find the number of apples Alan had at first?
5x = 3y
5(x - 30) = y
5x = 3*5(x - 30) = 15(x - 30) = 15x - 450
10x = 450
x = 45 (Alan), y = 75 (Don)
