Quantitative Aptitude · Reasoning

Time and Clocks

562 Questions

Time and clocks problems evaluate quantitative aptitude by testing concepts on clock gains, losses, and relative speeds of hands. Questions also cover global time zones and standard time calculations. These logical reasoning topics frequently appear in SSC and banking exams.

Clock gain or lossTime zonesAngle between handsStandard time calculationPrecise time measurement

Time and Clocks Questions

Multiple choice conversion of time time conversion time measurement of time maths

If a clock strikes $12$ in $33$ seconds, it will strike $6$ in how many seconds?

  1. $\displaystyle \frac{33}{2}$
  2. $15$
  3. $12$
  4. $22$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In order to strike 12 there are 11 intervals of equal time = $\displaystyle \frac{33}{11}$ = 3 seconds each
Therefore to strike 6 it has 5 equal intervals, it requires 5 $\displaystyle \times $ 3 =15 sec.

Multiple choice lorentz transformation and muon experiment option a: relativity physics

The minute hand of the clock is 4 cm long. The average velocity of the tip of the minute hand between 11:00 am to 11:30 am is:

  1. $1.5\times { 10 }^{ -5 }{ m }/{ s }$
  2. $4.4\times { 10 }^{ -5 }{ m }/{ s }$
  3. $1.8\times { 10 }^{ -6 }{ m }/{ s }$
  4. $3.5\times { 10 }^{ -6 }{ m }/{ s }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average velocity $ = \dfrac{Total \; Displacement}{Total \; Time}$


$ = \dfrac{  2\times 0.04}{30 \times 60} = 4.44 \times 10^{-5} \;m/s$

Multiple choice lorentz transformation and muon experiment option a: relativity physics
Two clocks are running in synchronism. One clock is moved at a very high speed and returned to the original position on the earth while the other remains at rest. The time passed in the travelling clock is 1 hr. Which of the following could be the time passed in the clock kept on the earth.

  1. 30 minutes

  2. 45 minutes

  3. 59 minutes

  4. 1 hours

  5. 2 hours
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

According to the time dilation concept of relativity, the moving clock runs at slower rate than the rest clock  i.e rest clock measures longer time taken by an event than the moving clock.

Hence time elapsed in the clock kept on earth must be greater than 1 hr.
So, option E is correct.

Multiple choice evs magic with mirrors lateral inversion right or left reflection at plane surface

A clock fixed on a wall shows time $04:25:37$. What time will its image in a plane mirror show?

  1. $07:43:32$
  2. $07:43:32$
  3. $07:35:23$
  4. $43:27:36$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Given that in question actual time and its image will show same interpreted time at  06:00:00 and 12:00:00
  • Now , 06:00:00 - 04:25:37 = 01:34:23. This means the time 04:35:27 is 1 hour 34 minutes and 23 seconds to 06:00:00.
  • So the interpreted image of this time is 1 hour 34 minutes and 27seconds past  06:00:00; that is, 07:34:27
  • Hence the option C is the right answer
Multiple choice evs magic with mirrors lateral inversion right or left reflection at plane surface

A clock fixed on a wall shows time 04 : 25 : 37. Its image in a plane mirror shows :

  1. 07 : 30 : 33

  2. 07 : 43 : 32

  3. 07 : 35 : 22

  4. 43 : 27 : 36
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

After reflection,
Image of the hour hand will look like its pointing between 7 and 8.
Image of the minute hand will look like its pointing at 7.
Image of the hour hand will look like its pointing between 4 and 5.
So the time will appear to be $07 : 35 : 22$

Multiple choice maths how much does it weigh? basic operations with same units operations involving units of length calculations define weight and units of weight

Calculate the time $1:30+4:45$.

  1. $5:15$
  2. $5:45$
  3. $6:15$
  4. $6:45$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$1:30+4:45$

Adding hours $=1+4=5$ hours
Adding minutes $30+45=75$ minutes
Now $60$ minutes $=1 $ hour
$\therefore 75$ minutes $=1$ hour $+15$ minutes
So total time is $(5+1=6)$ hours and  $15$ minutes 
$=6:15$

Multiple choice maths how much does it weigh? basic operations with same units operations involving units of length calculations define weight and units of weight

Gabriel watched $3$ old movies on videotape. The first movie was $62$ minutes long. The
second was $1$ hour $34$ minutes long. The third was $1$ hour $25$ minutes long. He started
watching at $3:15$ P.M. At what time did the last movie end?

  1. $7:00$ P.M.
  2. $7:08$ P.M.
  3. $7:12$ P.M.
  4. $7:16$ P.M.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

First movie $62$ min.

Second movie $94$ min
Third movie $85$ min
so total time of movie will be $241$ minutes
which makes $4$ hours and 1 minute
So he should finish $3:15 + 4:01$ = $7:16 $ P.M.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

Which of the following time measuring devices is most precise?

  1. A wall clock

  2. An atomic clock

  3. A digital watch

  4. stop watch
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Option $(B)$ is correct because a clock can measure time correctly up to one second. A stopwatch can measure time correctly up to a fraction of a second. A digital watch can measure time up to a fraction of second whereas an atomic clock is the most accurate timekeeper and is based on characteristic frequencies of radiation emitted by certain atoms having a precision of about $1$ second in $300,000$ years. So an atomic clock can measure time most precisely as the precision of this clock is about $1 s$ in $10^{13} s$.

Multiple choice maths construction of angles angles in a clock checking angles between hands of a clock clock with respect to angles measuring and drawing angles

At 5'O clock the angle between two hands in a clock is 

  1. ${ 120 }^{ \circ }$
  2. ${ 130 }^{ \circ }$
  3. ${ 140 }^{ \circ }$
  4. ${ 150 }^{ \circ }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A clock has $12$ equal parts$={360}^{\circ}$
$1$ part$=\dfrac{{360}^{\circ}}{12}={30}^{\circ}$
At $5$O clock the hands will be between $12$ and $5=5$parts
$\therefore 5$ parts$=5\times{30}^{\circ}={150}^{\circ}$
Multiple choice maths construction of angles angles in a clock checking angles between hands of a clock clock with respect to angles measuring and drawing angles

The centre of a clock is taken as origin At 4.30 pm the equation of line along minute hand is x = 0 Therefore at this istant the equation of line along the hour hand will be 

  1. $x - y = 0$
  2. $x + y = 0$
  3. $\displaystyle y=\sqrt{2x}$
  4. $\displaystyle y=\frac{x}{\sqrt{2}}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The centre of a clock is taken as origin. At 4:30 pm equation of line along minute hand is $x=0$.
Therefore at this instant the equation of line along the hour hand will be 
$m=-1$ ( as tan 135=-1 )
Therefore equation of line y=mx
or $y=-x$
$y+x=0$.