Final answer:
To convert 9 pairs of trousers to minutes and hours, multiply the given time for 1 pair of trousers by 9. Then, divide the total minutes by 60 to convert to hours. Hence the correct answer is option D
Step-by-step explanation:
To convert 9 pairs of trousers to minutes and hours, we need to multiply the given time for 1 pair of trousers (57 minutes) by 9. This gives us 9 * 57 = 513 minutes. To convert minutes to hours, we divide the total minutes by 60. 513 minutes ÷ 60 = 8 hours and 33 minutes. Therefore, the answer is d) 513 hours.