A clock is set right at 12 noon on Monday. It losses 1/2 % on the correct time in the first week but gains 1/4 % on the true time during the second week. The time shown on Monday after two weeks will be

Answer: Option B

Time lost over two weeks = 25% a week time(given that $$\frac{1}{2}$$ % clock loses in first week and in the second week it gains $$\frac{1}{4}$$ % on true time)
A week = 168 hours
Hence, clock lost = 0.42 hours = 25.2 minutes or 25 minute 12 seconds
Thus, correct time = 11 : 34 : 48