A clock shows the time as 6 a.m. If the minute hand gains 2 minutes every hour, how many minutes will the clock gain by 9 p.m.?

From 6 a.m. to 9 p.m. is a 15-hour period (6 am to 6 pm = 12 hours, plus 3 more hours to 9 pm). If the minute hand gains 2 minutes every hour, total gain = 15 hours × 2 minutes/hour = 30 minutes. Option A is correct. Option B (25), C (28), and D (34) are miscalculations. The key is correctly counting the hours and multiplying by the gain rate.