Practice Faulty clocks - verbal reasoning Online Quiz (set-1) For All Competitive Exams
Q-1) Two clocks are set correctly at 10 am on Sunday. One clock loses 3 min in an hour while the other gains 2 min in an hour. By how many minutes do the two clocks differ at 4 pm on the same day ?
(a)
(b)
(c)
(d)
Clearly, Raveena left home 10 min before 8 : 40 am i.e., at 8 : 30 am
but it was 15 min earlier than usual,
so she usually leaves for the stop at ( 8 : 30 + 0 : 15 ) = 8 : 45 am.
Q-2) Imagine that your watch was correct at noon, but then it began to lose 30 minutes each hour. It now shows 4 p.m. but it stopped 5 hours ago. What is the correct time now?
(a)
(b)
(c)
(d)
The watch loses 1/2 hour each hour.
So, it must have taken 8 hours to show 4 p.m. from 12 noon.
Thus, it stopped at 8 p.m. So, the correct time is 5 hours ahead of 8 p.m., i.e., 1 a.m.
Q-3) A watch goes fast by 15 minutes compared to the right time everyday. If it is corrected and set to the standard time at 120' clock at noon, which of the following will be the time shown by it at 4:00 a.m. in the morning?
(a)
(b)
(c)
(d)
Duration from 12 noon to 4:00 a.m. = 16 hours.
Time gained in 24 hours = 15 min.
Time gained in 16 hours = (5/24 × 16) min = 10 min.
Q-4) A clock goes slow from midnight by 5 minutes at the end of the first hour, by 10 minutes at the end of the second hour, by 15 minutes at the end of the third hour and so on. What will be the time by this clock after 6 hours?
(a)
(b)
(c)
(d)
Time lost I 1 hour = 5 min. Time lost in 6 hours = (5 × 6) min = 30 min.
After 6 hours, the correct time will be 6 a.m. and the clock will show 5.30 a.m.
Q-5) A clock, which loses uniformly, is 15 min fast at 9 am on 3rd of the December and is 25 min less than the correct time at 3 pm on 6th of the same month. At what time it was correct?
(a)
(b)
(c)
(d)
Time of the last train leaving the station = (18 : 00 - 2 : 30)h = 15 : 30h
But this happens 40 min before the announcement is made.
Hence, Time of making announcement = (15 : 30 + 0 : 40) = 16 : 10h
Q-6) A clock is set right at 5 am. The clock loses 16 min in 24 h. What will be the right time when the clock indicates 10 pm on the 3rd day?
(a)
(b)
(c)
(d)
Time from 5 am of a particular day to 10 pm on the 3rd day is 89 h.
Now, the clock loses 16 min in 24 h or in other words,
we can say that 23 h 44 min of this clock is equal to 24 h of the correct clock.
$(23 + 44/60) = 356/15$ h of this clock = 24h of the correct clock
Therefore, 89 h of this clock = $(24 × 15 / 356 × 89) h$
the correct clock = 90 h of the correct clock or 89 h of this clock = 90 h of the correct clock.
Therefore, it is clear that in 90 h this clock loses 1 h and hence, the correct time is 11 pm when this clock shows 10 pm.
Q-7) A watch is 1 minute slow at 1 p.m. on Tuesday and 2 minutes fast at 1 p.m. on Thursday. When did it show the correct time?
(a)
(b)
(c)
(d)
Time from 1 p.m. on Tuesday to 1 p.m. on Thursday = 48 hours.
So, the watch gains (1 + 2) min or 3 min in 48 hrs.
Now, 3 min are gained in 48 hrs. So, 1 min is gained in (48/3) = 16 hrs.
Q-8) A watch, which gains uniformly is 2 min slow at noon on Monday and is 4 min, 48s fast at 2 pm on the following Monday. At what time it was correct?
(a)
(b)
(c)
(d)
(e)
Time from Monday noon (12 pm) to 2 pm the following Monday = 7 days 2 h = 170 h
Now, the watch gains (2 + 4 4/5) min from Monday (12 pm) to 2 pm,
the following Monday. In other words, the watch gains 34/5 min in 170 h.
Therefore, it will gain 2 min in (170 × 5/34 × 2) = 50 h = 2 days 2 h
Therefore, the watch is correct after 2 days 2 h from Monday noon or at 2 pm Wednesday.
Q-9) A clock becomes 12 s fast in every 3 h. If it is made correct at 3 O' clock in the afternoon of Sunday, then what time will it show at 10 O' clock Tuesday morning?
(a)
(b)
(c)
(d)
Total time from 3 O' clock Sunday afternoon to 10 O' clock Tuesdy morning = 43 h
Total increased time = 12/3 × 43 = 172s = 2 min 52s
Therefore, Time at 10 O' clock Tuesday morning = 2 min 52 s past 10
Q-10) A mechanical grandfather clock is at present showing 7 hr 40 min 6 sec. Assuming that it loses 4 seconds in every hour, what time will it show after exactly 6 $1/2$ hours?
(a)
(b)
(c)
(d)
Time lost in 6 $1/2$ hours = $(6 1/2 × 4) $sec = 26 sec.
Correct time after 6$ 1/2$ hours = 7 hr 40 min 6 sec + 6 hr 30 min = 14 hr 10 min 6 sec.
Time shown by the clock = 14 hr 10 min 6 sec - 26 sec = 14 hr 9 min 40 sec.