If the number of pages seen is x, the remaining pages are 200-x. According to the meaning of the question, the equation can be listed: x = 60% (200-x) To simplify it: x = 60% × 200 - 60% × x To solve the equation: 120 - 30% × x = 200 30% × x = 80 x = 240 Therefore, the number of pages he had seen was 240.