CALENDAR & CLOCKS

ODD DAYS : Number of days more than the complete of weeks in a given period is the number of odd days during that period.

LEAP YEAR : Every year which is divided by 4 is called a leap year. E.g. 1992,1996,2001,2008 etc

CLOCK : The face or dial of a watch is a circle whose circumference is divided into 60 equal parts called minute spaces.

A clock has two hands, the smaller one is called the hour hand or short hand while the larger one called the minute hand or long hand.

Results

#1. On what dates of July 2004 did Monday fall ?

On what dates of July 2004 did Monday fall ?

Let us find the day on 1st July,2004

2000 years have 0 odd day. 3 ordinary years have 3 odd days.

Jan (plus) Feb. (plus) March (plus) April (plus)  May (plus)  June (plus) July

31  (plus)  29   (plus)     31  (plus)    30 (plus)    31 (plus)    30  (plus)    1

=183 days

=(26 weeks (plus) 1 day)

=1 odd day

Total number of odd days= (0 (plus) 3 (plus) 1) odd days

=4 odd days

1st Monday in July 2004 was on 5th July

5th, 12th, 19th and 26th.

#2. What was the day of the week on 16th April 2000 ?

What was the day of the week on 16th April 2000 ?

16th April, 2000= (1999 years (plus) Period from 1st Jan.,2000 to 16th April, 2000)

Counting of Odd days :

1600 years have 0 odd day. 300 years have 1 odd day.

99 years = (24 leap years (plus)75 ordinary years)

= [(24*2) (plus)(75 * 1)] odd days

=123 odd days

(17 weeks (plus)4 days)

= 4 odd days

Jan (plus) Feb. (plus) March (plus) April

31 (plus)   29  (plus)     31  (plus)   16

= 107 days

= (15 weeks (plus)2days)

=2 odd days

Total number of odd days = (0 (plus) 1 (plus) 4 (plus) 2)

odd days = 7 Odd days

0 odd day

The required day was ‘Sunday’

#3. Today is Friday. After 62 days, it will be :

Today is Friday. After 62 days, it will be :

Each day of the week is repeated after 7 days. so after 63 days, It will be Friday.

Hence, after 62 days, it will be Thursday.

#4. On what dates of April 2001 did Sunday fall ?

On what dates of April 2001 did Sunday fall ?

Find the day on 1st April, 2001, 2000 years contain 2 odd days

Jan (plus) Feb (plus) March (plus) April

31 (plus)  28 (plus)     31  (plus)     1= 91 days

= 13 weeks 0 day

= 0 odd day

Sunday fell on 1st, 8th,15th,22nd and 29th of April 2001.

 

#5. The First Republic Day of India was celebrated in 26th January,1950.It was:

The First Republic Day of India was celebrated in 26th January,1950.It was:

26th Jan., 1950=(1949 years (plus) period from 1st jan., 1950 to 26th Jan., 1950)

1600 Years have  0 odd day. 300 Years have 1 odd day.

49 years = (12 leap years (plus) 37 ordinary Years)

=[(12 *2) (plus)(37 * 1) ] odd days =61 odd days

=5 odd days

Number of days from 1st Jan. to 26 th Jan.=26=5 Odd days

The required day was ‘ Thursday’

#6. January 1, 2004 was a Thursday. What day of the week lies on Jan 1, 2005 :

January 1, 2004 was a Thursday. What day of the week lies on Jan 1, 2005 :

The year 2004 being a leap year it has 2 odd days.

So, first day of 2005 will be 2 days

beyond Thursday and so it will be Saturday

#7. On 8th March, 2005, Wednesday falls. What day of the week was it o 8th March, 2004 ?

What was the day of the week on 28th May, 2003 ?

The year 2004 being a leap year, it has 2 odd days.

So, the days on 8th March, 2005 will two days beyond the day on 8th March, 2004

But,8th March, 2005 is Wednesday

So,8th March 2004 is Monday

 

 

#8. What was the day of the week on 28th May, 2003 ?

What was the day of the week on 28th May, 2003 ?

2000 year have 2 odd days

The years 2001 and 2002 have (1 plus 1 ) = 2 odd days

Jan. 31 (plus) Feb 28 (plus) March 31 (plus) April 30 (plus) May 28 (plus)

=148 days = 21 weeks plus 1 day = 1 odd days

Total number of odd days = (2 plus 2 plus 1 plus ) = 5

The required day was ’Friday’

#9. At 3.40 the hours hand and the minutes hand of a clock from an angel of :

At 3.40 the hours hand and the minutes hand of a clock from an angel of :

Angle traced by hour hand in 12 hrs = 360°

Angle traced by it in 11/3 hrs = (360/12*11/3)° = 110°

Angle traced by minute hand in 60 min = 360°

Angle traced by it in min =(360/60*40) = 240°

∴ Required angle (240 – 110)°

= 130°

#10. A clock is started at noon. By 10 minutes past 5, the hour had has turned through :

A clock is started at noon. By 10 minutes past 5, the hour had has turned through :

Angle traced by hour hand in 12 hrs = 360°

Angle traced by hour hand in 5 hrs 10 min i.e 31/6 hrs

=  (360/12*31/6)°

= 155°

#11. How many times do the hands of a clock coincide in a day ?

How many times do the hands of a clock coincide in a day ?

The hands of a clock coincide 11 times in every 12 hours

∴The hands coincide 22 times in a day

#12. How many times are the hands of a clock at right angle in a day ?

How many times are the hands of a clock at right angle in a day ?

In 12 hours, they are at right angles 22 times.

∴ in 24 hours they are at right angle 44 times.

#13. How many times in a days the hands of a clock are straight ?

How many times in a days the hands of a clock are straight ?

In 12 hours, the hands coincide or are in opposite direction 22 times

In 24 hours the hands coincide or are in opposite direction 44 times a day

#14. An accurate clock shows 8 of clock in the morning through how many degrees will the hour hand rotate when the clock shows 2 of clock in the afternoon ?

An accurate clock shows 8 of clock in the morning through how many degrees will the hour hand rotate when the clock shows 2 of clock in the afternoon ?

Angle traced by the hour hand in 6 hours = (360/12*6)°

= 180°

#15. The angle between the minutes hand and hour hands of a clock when the minutes is :

The angle between the minutes hand and hour hands of a clock when the minutes is :

Angle traced by hour hand in 17/2 hrs = (360/12*17/2)°= 255

Angle traced by ,min hand in 30 min = ( 360/60*30)° = 180

∴ Required angle = ( 255 – 180)°

= 75

#16. At what time between 5.30 and 6 will the hands of a clock be at right angles ?

At what time between 5.30 and 6 will the hands of a clock be at right angles ?

At  5 O’clock, the hands are 25 min. spaces apart.

55 min. spaces are gained in 60 min

40 min. spaces are gained in (60/55 * 40) min.

43 ⁷⁄₁₁ min. past 5

#17. How many time in a day, the hands of a clock are straight ?

How many time in a day, the hands of a clock are straight ?

In  12 hours, the hands coincide or are in opposite direction 22 times

In 24 hours, the hands coincide or are in opposite direction 44 times a day

#18. How many times are the hands of a clock at right angle in a day ?

How many times are the hands of a clock at right angle in a day ?

In 12 hours, they are at right angles 22 times.

In 24 hours, they are right angles 44 times.

#19. At what time between 9 and 10 O'clock will the hands of a watch be together?

At what time between 9 and 10 O’clock will the hands of a watch be together?

45 min are gained in (60/55 *45)min.

=49 ¹⁄₁₁ min past 9

#20. The angle between the minute hand and the hour hand of a clock when the time is 8.30 is:

The angle between the minute hand and the hour hand of a clock when the time is 8.30 is:

Angle traced by hour hand in 17/2 hrs=(360/12*17/2)°=225

Angle traced by min. hand in 30 min.= (360/60*30)°=180

required angle=(255-18)

75°

Finish

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