Answer: B Time from monday noon(12 pm) to 2 pm the following monday => 7 days 2 hour = 170 hr Now, the watch gains (2+ 24/5) min from monday So, the watch gains 34/5 min in 170 hours. Therefore, it will gain 2 min in 50 hr = 2 days 2 hour. Therefore the watch is correct after 2 days 2 hour from monday noon or at 2 pm on wednesday.
Q. No. 2:
A clock is set right at 5 am. The clock loses 16 min in 24 hours. What will be the right time when the clock indicates 10pm on the 4th day?
Answer: B Time from 5 am of a particular day to 10pm on the 4th day is 89hr. Now clock loses 16min in 24 hr or in other words we can say that 23 hr 44 min of this clock is equal to 24hr of the correct clock. or (23 + 44/60) => 365/15 hr of this clock = 24 hr of the correct clock. 89 hr of this clock = {(24*15)/356}* 89 hr = 90 hr of the correct clock. or 89 hours of this clock = 90 hr of the correct clock Therefore, it is clear that 89 hr this clock loses 1 hr and hence correct time is 11pm, when the clock shows 10pm.
Q. No. 3:
A clock gaining 2 min every hour was synchronised at midnight with a clock losing 1 min every hour. How many minutes the clock (losing time)will be behind at eleven in the following morning?
Answer: D Suppose both the clocks at 12pm. In the following morning 11 am, the gaining clock is 22 min ahead and losing clock is 11 min behind from the real time. The clock losing the time is 33 min behind the clock gaining the time.
Q. No. 4:
At what angle the hands of a clock are inclined at 15 minutes pasts?
Answer: B At 15 min past 5, the minutes hand is at 3 and hour hand slightly ahead of 5. Now, the angle through which hour hand shifts in 15 min = (15 * 1/2) = 7.5 degree Angle at 15 min past 5 = 60 + 7.5 = 67.5o
Q. No. 5:
When do the hands of a clock coincide between 4 and 5?
Answer: A At 4 the minutes hand is 4*30 = 120 degree behind the hour hand. The minutes hand takes a lead of 11/2 degree every minute over the hour hand. The time it takes to catch up 120 degree = 120/(11/2) = 240/11 min after 4 This is when they would coincide.
Q. No. 6:
Two clocks show the same time at 4 pm. The first clock loses 10 min every 2 hour and the second gains 10 min every hour. When will they both show the same time again?
Answer: C If they had not lost or gained any time, they would both show the same time always. But in this case, the first clock would be behind the second clock by 15 min at the end of 1 hour. (Since the first clock loses 5 min and the second gains 10 min in 1 hour)They would both show the same time again if they are separated by 12 hr = 12* 60 mins Number of hours the first clock takes to be behind the second by 12 hr => (12*60)/15 = 48 hr So they would show the same time again after exactly 2 days.
