Olympiad Verbal - Clock
Exam Duration: 45 Mins Total Questions : 20
A bus for the station from Boring Road leaves after every half an hour. An enquiry clerk told a passenger that the last bus had left at 9:10 and the next bus leaves after 15 minutes. At what time did the enquiry clerk give this information to the passenger?
- (a)
7:50
- (b)
9:25
- (c)
8:75
- (d)
10
The interval of two leaving buses = 30 minutes
The time for the next bus = 15 minutes.
∴ Time passed = 30 - 15
= 15 minutes
∴ The required time for the information given by enquiry clerk
=9:10 + 0:15
=9:25.
A clock is set right at 5 am. The clock loses 16 minutes in 24 hours. What will be the right time when the clock indicates 10 pm on the 3rd day?
- (a)
11:15pm
- (b)
11 pm
- (c)
12 pm
- (d)
12:30pm
Time from 5 am of a particular day to 10 pm on the 4th day is 89 hours. Now, the clock loses 16 minute in 24 hours or in other words, we can say that 23 hours 44 minutes of this clock is equal to 24 hours of the correct clock.
or \(\left(23+{44\over 60}\right)⇒{356\over 15}\) hours of this. clock = 24 hours of the correct clock.
∴ 89 hours of this clock = \(\left({24\times15\over 356}\times89\right)\) hours of correct clock.
= 90 hours of the correct clock
or 89 hours of this clock = 90 hours of the correct clock. Therefore, it is clear that in 89 hours this clock loses 1 hour and hence the correct time is 11 pm when this clock shows 10 pm.
At what and Ie are the hands of a clock inclined when it is half past 8?
- (a)
25°
- (b)
45°
- (c)
75°
- (d)
35°
At half past 8, the minute hand points towards 6 and the hour hand points towards \(2{1\over2}\)marks between 8 and 9. The angle between 6 and 8 is 60° and the angle for \(2{1\over2}\)a minute space
\(=2{1\over 2}\times6\)
=150
∴ Total angle between the two hands
= 60° + 15°
= 75°
How many tirnes do the hands of a clock coincide in a day?
- (a)
24
- (b)
22
- (c)
21
- (d)
20
From the properties. of the clock we known that the hands of a clock coincide in every hour but between 11 O'clock and 1 O'Clock they coincide only once. Therefore, the hands of a clock coincide 11 times in every 12 hours. Hence, they will coincide (11 x 2) = 22 times in 24 hours. So, the correct answer is (B).
A watch, which gains uniformly, is 2 minute slow at noon on Monday, and is 4 minute, 48 sec fast at 2 pm on the following Monday. At what time was it correct?
- (a)
2 pm on Tuesday
- (b)
2 pm on Wednesday
- (c)
3 pm on Thursday
- (d)
1 pm on Friday
Time from Monday noon (12 pm to 2 pm the following Monday
= 7 days 2 hours = 170 hours
Now, the watch gains \(\left(2+4{4\over 5}\right)\) minute from Monday (12 pm) to 2 pm on the following Monday.
or in other words, the watch gains \(34\over 5\) minutes in 170 hours. Therefore, it will gain 2 minute in \(\left({170\times5\over 34}\times2\right)\)hours
= 50 hours
= 2 days 2 hours
Therefore, the watch is correct after 2 days 2 hours from Monday noon or at 2 pm on Wednesday. So, the correct option is (B).
The priest told the devotee, "The temple bell is rung at regular intervals of 45 minutes.The last bell was rung 5 minutes ago. The next bell is due to be rung at 7:45 a.m." At what time did the priest give this information to the devotee?
- (a)
7:40 a.m.
- (b)
7:05 a.m.
- (c)
7:00 a.m.
- (d)
6:55 a.m.
The last bell rung at 7.45 - 0.45 = 7.00 a.m.
But this happened 5 minutes before
Hence, the information was given at 7.05 a.m.
A clock is set to show the correct time at 8 a.m. The clock gains 10 minutes in a day. What will be the approximate time, when the watch indicates 4 p.m. the next day?
- (a)
3 h 36 min
- (b)
3 h 47 min
- (c)
3 h 50 min
- (d)
3 h 54 min
At what time between 7 and 8 O'clock will the hands of a clock be in the same straight line but, not together?
- (a)
5 minutes past 7
- (b)
\(5{2\over 11}\) minutes past 7
- (c)
\(5{3\over 11}\) minutes past 7
- (d)
\(5{5\over 11}\) minutes past 7
When the hands of the clock are in the same straight line but not together, they are 30minute spaces apart. At 7 O'clock, they are 25 min. spaces apart.
∴ Minute hand will have to gain only 5 min. spaces
55 min. spaces are gained in \(\left({60\over 55}\times5\right)\) min. or \(5{5\over 11}\) min. required time = \(5{5\over 1}\) min. past 7.
How many times in a day, are the hands of a clock in straight line but opposite in direction?
- (a)
20
- (b)
22
- (c)
24
- (d)
48
The hands of a. clock point in opposite directions (in the same straight line) 11 times in every 12 hours (Because between 5 and 7 they point in opposite directions at 6 O'clock only). So, in a day, the hands point in the opposite directions 22 times
A clock is set right at 8 am. The clock gains 10 minutes in 24 hours. What will be the right time when the clock indicates 1 pm on the following day?
- (a)
11:40p.m.
- (b)
12:48 p.m.
- (c)
12 pm
- (d)
10 pm
Time from 8 am of a particular day to 1 pm on the following day = 29 hours
Now the clock gains 10 minutes in 24 hrs, which means that 24 hours 10 minutes of this clock is equal to 24 hours of the correct clock
\(145\over 6\)hours of this clock = 24 hours of the correct clock
29 hours of the clock \(={24\over 145}\times6\times29\)
= 28 hours, 48 minutes of correct clock
It means that the clock in question is 12 minutes faster than the correct clock. Therefore, when clock indicates 1 pm the correct time will be 48 minutes past 12.
A bus for 80mbay leaves every 40 minutes from a bus stand. An enquiry clerk told a person that the bus had already left 10 minutes ago and the next bus will leave at 10:45 a.m. At what time this information was given to the man?
- (a)
10:45a.m.
- (b)
9:55a.m.
- (c)
10:35a.m
- (d)
10:15a.m.
Reqd. time = (10.45 - 0.40) + 0.10
= 10.15 a.m.
In \(1\over 2\) hour, the minute hand of clock will rotate through an angle of:
- (a)
750
- (b)
600
- (c)
1200
- (d)
1800
In \(1\over 2\)hour the middle hand will move through
\(={1\over 2}\times360^0=180^0\)
At what time between 5 and 6 are the hands of a clock coincident?
- (a)
22 minute past 5
- (b)
30 minute past 5
- (c)
\(22{8\over 11}\) minute past 5
- (d)
\(27{3\over 11}\) minute past 5
From the given figure, we find that minute hand is 25 minute spaces apart from hour hand. In order to coincide it has to gain 25 minute spaces
Now, 55 minutes are gained by minute hand in 60 minutes.
So, 25 minutes will be gained in
\({60\over 55}\times25=27{3\over 11}\)minutes.
So the hands will coincide at \(27{3\over 11}\)
The bus for Jaipur leaves every 25 minutes. An enquiry clerk told that last bus for Jaipur had already left 10 minutes to 2:00 p.m. At what time the next bus will leave for Jaipur?
- (a)
2:25 p.m.
- (b)
2:15 p.m.
- (c)
2:05 p.m.
- (d)
2:40 p.m.
Interval between two leaving buses = 25 minutes.
Time of leaving of the last bus = 1.50 p.m.
Therefore, the reqd. time for the next bus = 1.50 + 0.25 = 2.15 p.m.
At what time between 5:30 and 6 will the hands of a clock be a right angles?
- (a)
\(43{5\over 11}\) minute past 5
- (b)
\(43{7\over 11}\) minute past 5
- (c)
40 minute past 5
- (d)
45 minute past 5
At 5 O'clock, the hands are 25 min. spaces apart. To be at right angles and that too between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 min. spaces. 55 min. spaces are gained in 60 min.
40 min. spaces are gained in \(=\left({60\over 55}\times40\right)min=43{7\over11}min\)
∴ Required time \(43{7\over 11}\) minute past 5
How much does a watch lose per day, if its hands coincide every 64 minutes?
- (a)
\(32{8\over 11}min\)
- (b)
\(36{5\over 11}min\)
- (c)
90 min.
- (d)
96 min
55 min. spaces are covered in 60 min.
60 min. spaces are covered in \(={65{5\over 11}}min\)
Loss in 64 min =\(\left(65{5\over 11}-64\right)={16\over 11}min\)
Loss in 24 hrs = \(\left({16\over 11}\times{1\over64}\times24\times60\right)min.=32{8\over 11}min\)
At what ti.me betewen 9 and 10 O'clock will the hands of a watch be together?
- (a)
45 minutes past 9
- (b)
50 minutes past 9
- (c)
\(49{1\over 11}\)minutes past 9
- (d)
\(48{2\over 11}\)minutes past 9
Both the hands are 15 minute space apart at 9 O'clock.
To be together between 9 and 10, minute hand has to gain 45 minutes. 2.
Now, minute hand gains 55 minutes in 60 minutes.
It will gain 45 minutes in \({60\over 55}\times45=49{1\over 11}\)minutes
Therefore, the hands are together at \(49{1\over 11}\)minutes past 9
A tired worker slept 6:45p.m. If the rose at 12 noon, for how many hours did he sleep?
- (a)
17 hours 15 minutes
- (b)
5 hours 15 minutes
- (c)
12 hours
- (d)
6 hours 45 minutes
Duration of his sleep = (12 - 6.45) + 12
=5.15+12
= 17 hours 15 min.
How many times do the hands of a clock point towards each other in a day?
- (a)
24
- (b)
20
- (c)
12
- (d)
22
The hands of a clock point towards each other 11 times in every 12 hour (because between 5 and 7, they point towards each other once at 6 O'clock). Therefore, in a day the hands points 22 times towards each other.
How many any times from 5 a.m. t 0 5 p.m. the hands are at right angels?
- (a)
24
- (b)
22
- (c)
16
- (d)
21
The hands are at right angles 22 times in every 12 hours