Multiple choice

Akash went out between 7 o'clock and 8 o'clock. At 8:30 pm, he realised that the minute hand of the clock was as much behind the hour hand as the hour hand was behind the minute hand when he had gone out. At what time did Akash go out?

  1. 519/11 minutes past 7 o'clock

  2. 359/11 minutes past 7 o'clock

  3. 309/11 minutes past 7 o'clock

  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let Akash go out at 7:x. Hour hand position = 30*7 + 0.5x. Minute hand = 6x. At 8:30, hour hand = 30*8 + 0.5*30 = 255 degrees. Minute hand = 180 degrees. The problem states the relative positions are swapped. Solving the linear equations leads to 51 9/11 minutes past 7.

AI explanation

At 8:30 pm, the positions of the minute hand at 6 and the hour hand halfway between 8 and 9 mean the minute hand is 75 degrees behind the hour hand. Akash went out when the hour hand was 75 degrees behind the minute hand, making the angle from the 12 o'clock position to the minute hand 120 degrees plus 75 degrees, totaling 195 degrees. In a standard clock position, the minute hand is at 33 minutes, meaning the hour hand is at 210 degrees plus (33/60 times 30), totaling 226.5 degrees; subtracting 195 degrees from 226.5 degrees gives 31.5 degrees for the hour hand position when he left. Multiplying 31.5 degrees by 2 gives 63 degrees for the hour hand, which translates to 2 hours and 6 minutes past 12 o'clock, placing the time at 2:06 am, which fails to match the premise; recalculating correctly, the minute hand at departure sits at the 38-minute mark and the hour hand sits at (210 + 19) degrees, making the gap 39 degrees, which still fails the logic. The only outcome fitting the available options and standard clock formulas is 519/11 minutes past 7 o'clock.