Q 7. Clocks and Calendars

Which date of June 2099 among the following is Sunday?

a) 4
b) 5
c) 6
d) 7
Answer: d
Practice This Question in Exam Mode

  •   We know that January 01, 2001 is Monday and December 31, 2000 is a Sunday (It is a fact).
  •   Total number of odd days between December 31, 2000  to June 1 2099:-
  •   There are 98 complete years + 5 months (Jan 2099 to May 2099) + One day of June (i.e. June 1)
  •   98 complete years have 24 leap years having 2 odd days each and 74 ordinary years having one odd day each.
  •   So total number of odd days in 98 years = 24×2 + 74×1 = 48 + 74 = 122 (i.e. 122/7 = 3 odd days).
  •   In year 2099 (Ordinary Year, having Feb of 28 days) Jan to May we will get number of days as follows 3 (Jan) + 0 (Feb) + 3 (March) + 2 (April) + 3 (May) + 1 (June) = 3 + 3 + 2 + 3 + 1 = 12 = 5 odd days (12/7)
  •   So, total odd days = 3 + 5 = 8 = 1 (remainder when we divide 8 by 7)
  •   Thus June 1, 2099 will be Monday. (considering 31 dec 2000 as base)
  •   So, first Sunday of June will be on 7th.
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Q 35. Clocks and Calendars

How many seconds in total are there in x weeks, x days, x hours, x minutes and x seconds?

a) 11580x
b) 11581x
c) 694860x
d) 694861x
Answer: d
Practice This Question in Exam Mode

  •   1 day = 24 hr, 1hr = 60 minutes, 1minute = 60 seconds.
  •   So,  x minutes = 60 x seconds;
  •   x hours = 60 x minutes = 3600 x seconds;
  •   x days = 24 x hours = 24×60 x minutes = 24 × 3600 x seconds = 86400 x seconds;
  •   x weeks = 7 x days = 7 × 24 x hours = 7 × 24 × 60 x minutes = 7 × 24 × 3600 x seconds = 6,04,800 x seconds.
  •   Thus in x weeks, x days, x hours, x minutes and x seconds there will be
  •   6,04,800 x + 86400 x + 3600 x + 60 x + x = 694861 x seconds.
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Q 68. Clocks and Calendars

Consider the following statements:
 1. Between 3:16 p.m. and 3:17 p.m., both hour hand and minute hand coincide.
 2. Between 4:58 p.m. and 4:59 p.m., both minute hand and second hand coincide.
 Which of the above statements is/are correct?

a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Answer: c
Practice This Question in Exam Mode

  •   Formula – Angle between minute hand and hour hand θ = 11/2 M~30H.
  •   Where M is number of Minutes and H is number of Hours.
  •   Put θ = 0, and H = 3 to find M between 3 and 4, when both hands coincide.
  •   0 = 11/2 M – 30 × 3
  •   M = 16:36
  •   So the minute and hand will coincide at 3:16:36 which is between 3 and 4.Thus, statement, 1 is true.
  •   Hour hand and second hand coincide in once in every minute. So, statement, 2 will also be true.
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Q 7. Clocks and Calendars

From January 1, 2021, the price of petrol (in Rupees per litre) on m ^ (th) day of the year is 80 + 0 * 1m where m = 1, 2, 3 ,..., 100 and thereafter remains constant. On the other hand, the price of diesel (in Rupees per litre) on n ^ (th) day of 2021 is 69 + 0 * 15n for any n. On which date in the year 2021 are the prices of these two fuels equal?

a) 21 ^ (st) May
b) 20 ^ (th) May
c) 19 ^ (th) May
d) 18 ^ (th) May
Answer: b
Practice This Question in Exam Mode

  •   Let's calculate maximum value of petrol price = 80 + 0.1 × 100 = 90
  •   Now, equate it with the price of diesel
  •   90 = 69 + 0.15 × n
  •   n= (90-69)/0.15)= 140.
  •   2021 is non-leap year.
  •   31 + 28 + 31 + 30 + 20 = 140 days.
  •   Thus, 20th May is the required date.
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Q 57. Clocks and Calendars

At which one of the following times, do the hour hand and the minute hand of the clock make an angle of 180° with each other?

a) At 7:00 hours
b) Between 7:00 hours and 7:05 hours
c) At 7:05 hours
d) Between 7:05 hours and 7:10 hours
Answer: d
Practice This Question in Exam Mode

Option D: Between 7:05 hours and 7:10 hours
To determine when the hour and minute hands of a clock make an angle of 180°, we need to calculate the positions of the hands at different times.
     ● Step 1: Calculate the angle moved by the hour hand.  
           ○ The hour hand moves 360° in 12 hours, which is 30° per hour.
           ○ At 7:00, the hour hand is at 7 × 30° = 210°.
     ● Step 2: Calculate the angle moved by the minute hand.  
           ○ The minute hand moves 360° in 60 minutes, which is 6° per minute.
           ○ At 7:00, the minute hand is at 0°.
     ● Step 3: Determine the time when the angle between the hour and minute hands is 180°.  
           ○ Let the time be 7:x minutes.
           ○ The angle of the hour hand at 7:x is 210° + 0.5x° (since it moves 0.5° per minute).
           ○ The angle of the minute hand at 7:x is 6x°.
           ○ We need the absolute difference between these angles to be 180°:
         |(210+0.5x)6x|=180
         |2105.5x|=180
     ● Step 4: Solve the equation.  
           ○ Case 1: 2105.5x=180
         2105.5x=1805.5x=30x=305.55.45
           ○ Case 2: 5.5x210=180 (not possible as it would imply a negative x)
     ● Conclusion: The hands make an angle of 180° at approximately 7:05.45, which is between 7:05 and 7:10.  
     Therefore, the correct answer is Option D: Between 7:05 hours and 7:10 hours.
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Q 20. Clocks and Calendars

If in a particular year, 12 January is a Sunday, then which one of the following is correct?

a) 15 July is a Sunday if it is a leap year
b) 15 July is a Sunday if it is not a leap year
c) 12 July is a Sunday if it is a leap year
d) 12 July is not a Sunday if it is a leap year
Answer: c
Practice This Question in Exam Mode

No. of days in February is 29 if it is a leap year.

No. of days left in January = 31 - 12 = 19

Total no. of days till 12th July = (19 + 29 + 31 + 30 + 31 + 30 + 12) = 182

No. of odd days = 182 ÷ 7 = 26 weeks and 0 odd days.

Directions for the following 7 (Seven) items:

Read the following five passages and answer the items that follow. Your answers to these items should be based on the passages only.

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Q 49. Clocks and Calendars

A wall clock moves 10 minutes fast in every 24 hours. The clock was set right to show the correct time at 8:00 a.m. on Monday. When the clock shows the time 6:00 p.m. on Wednesday, what is the correct time?

a) 5:36 p.m.
b) 5:30 p.m.
c) 5:24 p.m.
d) 5:18 p.m.
Answer: a
Practice This Question in Exam Mode

  In 24 hours, the correct clock moves 24 × 60 = 1440 minutes, but the incorrect clock will move 1440 + 10 = 1450 min. So now we have basic relation between the correct and incorrect clock.

  Now by the condition given in question the incorrect clock has moved 24 + 24 + 10 = 58 hours (i.e. 58×60 minutes).

  If the incorrect clocks moves 1450 minutes, correct clock moves 1440 minutes.

  If the incorrect clock moves 1 minute, correct clock moves 1440/1450 minutes.

  But in our case incorrect clock has moved 58 hrs × 60 min /hr = 3480 minutes.

  So, if the incorrect clock moved 3480 minutes, the correct clock will have moved (1440×3480)/1450 = 3456 minutes.

  Converting 3456 min into hours we have 3456/60 = 573/5 or 57 hours 36 minutes.

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Q 59. Clocks and Calendars

Which year has the same calendar as that of 2009?

a) 2018
b) 2017
c) 2016
d) 2015
Answer: d
Practice This Question in Exam Mode

  To have the same calendar two things should be matched. First – the first day of the year and second – the year type i.e., ordinary or leap.

  Let the first day of year 2009 is X day. It means first day of 2010 will be X+1 day, as there is one odd day in one ordinary year.

  First day of 2011 will be X+2 day. (As there is one odd day in one ordinary year)

  First day of 2012 will be X+3 day. (As there is one odd day in one ordinary year)

  First day of 2013 will be X+5 day. (As there are TWO odd days in one LEAP year)

  First day of 2014 will be X+6 day. (As there is one odd day in one ordinary year); and

  First day of 2015 will be X+7 day. (As there is one odd day in one ordinary year)

  After every 7 days, the same day appears. So, the first day of 2015 will be same as 2009.

  Since both are ordinary years. We can use the calendar of 2009 in 2015.

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Q 41. Clocks and Calendars

A watch loses 2 minutes in every 24 hours while another watch gains 2 minutes in every 24 hours. At a particular instant, the two watches showed an identical time. Which of the following statements is correct if 24-hour clock is followed?

a) The two watches show the identical time again on completion of 30 days.
b) The two watches show the identical time again on completion of 90 days.
c) The two watches show the identical time again on completion of 120 days.
d) None of the above statements is correct.
Answer: d
Practice This Question in Exam Mode

  •   A watch loses 2 minutes in every 24 hours, while another watch gains 2 minutes in every 24 hours.
  •   Hence, every day the time difference between the two watches will keep on increasing by 4 minutes.
  •   They will again show the same identical time when this difference increases to 24 hours, i.e. 24 × 60 minutes or 1440 minutes.
  •   If 4 minutes are gained per day, then 1440 minutes will be gained in 1440 / 4 = 360 days.
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Q 43. Clocks and Calendars

A clock strikes once at 1 o'clock, twice at 2 o'clock and thrice at 3 o'clock, and so on. If it takes 12 seconds to strike at 5 o'clock, what is the time taken by it to strike at 10 o'clock?

a) 20 seconds
b) 24 seconds
c) 28 seconds
d) 30 seconds
Answer: b
Practice This Question in Exam Mode

  •   At 5 o’clock the clock will strike 5 times. It’s given that it takes 12 seconds to do so.
  •   Now, at 10 o’clock the clock will strike 10 times. Hence, the time taken by it to strike = 12 × 2 = 24 seconds
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Q 36. Clocks and Calendars

A class starts at 11:00 am and lasts till 2:27 pm. Four periods of equal duration are held during this interval. After every period, a rest of 5 minutes is given to the students. The exact duration of each period is:

a) 48 minutes
b) 50 minutes
c) 51 minutes
d) 53 minutes
Answer: a
Practice This Question in Exam Mode

  •   Class starts at 11:00 am and lasts till 2:27 pm.
  •   Total time = 207 minutes
  •   Total rest time = 3x5 = 15 minutes
  •   Effective time to be divided = 207 - 15 = 192 minutes
  •   Duration of one period = 194/4 = 48 minutes
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Q 68. Clocks and Calendars

Between 6 PM and 7 PM the minute hand of a clock will be ahead of the hour hand by 3 minutes at

a) 6 : 15 PM
b) 6 : 18 PM
c) 3 : 36 PM
d) 6 : 48 PM
Answer: c
Practice This Question in Exam Mode

We know that, exactly at 6 pm, angle between minute hand is 180°.

Now, to cover this angle, minute hand takes 180°/ 6° = 30 min.

Since, the minute hand is 3 min ahead of the hour hand.

Difference in angles = 3 x 5.5= 16.5°

  180° + 16. 5° = 6 x x - 0.5 (x - 3)

=  196.5 = 6x- 0.5x+ 1.5

=  195 = 5.5x = x = 195 / 5.5 = 35. 45 = 36 min

  Required time = 6 : 36 pm

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Q 12. Clocks and Calendars

Assume that
 1. the hour and minute hands of a clock move without jerking.
 2. the clock shows a time between 8 o'clock and 9 o'clock.
 3. the two hands of the clock are one above the other.
 After how many minutes (nearest integer) will the two hands be again lying one above the other?

a) 60
b) 62
c) 65
d) 67
Answer: c
Practice This Question in Exam Mode

Option C: 65
To solve this problem, we need to determine when the hour and minute hands of the clock will be aligned one above the other after initially being aligned between 8 o'clock and 9 o'clock.
  ● Step 1: Calculate the initial position of the hour and minute hands at 8 o'clock.  
        ○ At 8:00, the hour hand is at 240 degrees (since each hour represents 30 degrees, and 8 hours is \(8 \times 30 = 240\) degrees).
        ○ The minute hand is at 0 degrees.
  ● Step 2: Determine the rate of movement for each hand.  
        ○ The minute hand moves at 6 degrees per minute (since it completes 360 degrees in 60 minutes).
        ○ The hour hand moves at 0.5 degrees per minute (since it completes 30 degrees in 60 minutes).
  ● Step 3: Set up the equation for when the hands are aligned.  
        ○ Let \( t \) be the time in minutes after 8:00 when the hands are aligned.
        ○ The position of the minute hand after \( t \) minutes is \( 6t \) degrees.
        ○ The position of the hour hand after \( t \) minutes is \( 240 + 0.5t \) degrees.
  ● Step 4: Solve for \( t \) when the hands are aligned.  
        ○ The hands are aligned when their positions are equal:
      \[
      6t = 240 + 0.5t
      \]
        ○ Simplify the equation:
      \[
      6t - 0.5t = 240
      \]
      \[
      5.5t = 240
      \]
        ○ Solve for \( t \):
      \[
      t = \frac{240}{5.5} \approx 43.64
      \]
  ● Step 5: Calculate the next alignment after the initial one.  
        ○ The hands align every 360 degrees relative to each other.
        ○ The relative speed of the minute hand compared to the hour hand is \( 6 - 0.5 = 5.5 \) degrees per minute.
        ○ Time for the next alignment after the initial one:
      \[
      \frac{360}{5.5} \approx 65.45
      \]
  ● Step 6: Round to the nearest integer.  
        ○ The nearest integer to 65.45 is 65.
 Therefore, the two hands will be aligned again approximately 65 minutes after the initial alignment.
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