Skip to main content

Clock And Calendar

Hey guys ! It has been a very long time since we have learned something new. So now is the time we should start learning something new. Today I have selected two very basic but useful topics. If anyone of you is preparing for NTSE then these topics are must for your stage 2 Mental Ability. These are 2 very scoring topics which can get you good marks. So now let us begin with the learning.



   

Calendar

So the first topic which are going to study is Calendar. Let us first know how will this help. by learning the tricks of Calendar you can find out the day for a given date. For example : the given date is 26th January,1950. By looking at the date you cannot tell the day but after a few calculations you will be able to.


First thing and the basic thing for Calendar is "odd day". Now you must be wondering odd day means the third day or the fifth day but no. Odd day actually means the number of days left after a whole week is complete.. For better understanding let us take an example. Suppose you are asked to find out how many odd days are there in 45 days. For finding this you will simply divide the given number of days by 7. Why do we do so? We do this because one week completes in seven days, so 45 days actually means 6 weeks and 3 days. Those 3 extra days are known as odd days. Thus we can simply term odd days as the remainder left after diving the given days by 7.

Now you can find the odd days in a year also. So can you find the number of odd days in a year. Simple just divide 365 by 7 and the remainder is 1. So now we know that in a normal year there is 1 odd day and in a leap year there are 2 odd days. Now can you find how many odd days  are there in 100 years? You will first have to find the number of leap years and number of ordinary years and they are : leap year=24 and ordinary year=76. You will think that I have divided wrong but no every century year which is not divisible by 400 is not a leap year. So now calculating the number of odd days : 2 odd days in  a leap year and 1 in an ordinary year. Total= ( 24*2 + 76*1)/7 = 5 odd  days. Similarly in 200 years there are 3 odd days and in 300 years there is only 1 odd day. Now if you calculate for 400 years you will find that there is no odd day. 

So here we learn our second rule that every 400th year will have no odd day i.e. 800 years will have no odd day and so on. And every 100th , 200th and 300th year will have 5, 3 and 1 odd days respectively. So now I hope you can find out the number of odd days given any time period. If yes then congratulations because you have learnt 90% of Calendar. Now we come to the last rule before practicing and that is finding which day is on which odd day. For that you have to follow the table given below
Sunday - 0 odd days
Monday -1 odd day
Tuesday - 2 odd days
Wednesday - 3 odd days
Thursday - 4 odd days
Friday - 5 odd days
Saturday - 6 odd days

Yipee now we are all set to find the days. Let us start by taking the first example which we eventually took



26th January,1950 
For finding the day most simple way is that you divide the given date into different segments and they are
1) Nearest smaller 400th Century
2) Number of centuries 
3) Number of years excluding the given year 
4) All the months before the given month
5) Days in the given month

After you have done this you need to find the number of odd days in each segment and then finally total them and find the last number of odd days.

For the given date it will be 

1600          300             49          26
  0                1               5             5
Total = 11 = 4 odd days 
Therefore it was a Thursday on 26th January,1950.

Now if you were not able to understand then in the above line I have divided the date in the given segments and the lower line has the number of odd days in each segment. For finding the number of odd days in 49 years I first found out the number of leap years and then the number of ordinary years. Number of odd days in 49 years = ( 12*2 + 37*1)/7 = 5 odd  days.

Let us do some practice questions :

2nd October,1869

1600        200       68     Jan   Feb  Mar   Apr    May   Jun   Jul   Aug  Sep   2
  0              3          1       3      0       3       2         3       2     3      3      2      2

Total = 27 = 6 odd days
Therefore it was Saturday on the given date.

Key points to remember :
  • Never forget to consider the leap year. In a leap year February will have 1 odd day.
  • Be careful while dividing the years.
  • Always calculate the total number of odd days never miss any odd day.
  • Every year will repeat itself after 6 years or 11 years.
  • Every year one odd day will be added and in a leap year after February 2 odd days will be added.
I will be discussing the type of questions that come in the exam in the next article with the concepts of clock. Subscribe to our mailing list for daily updates and also follow us on Facebook ( www.facebook.com/highschoolpedia  )forgular news. I hope you enjoyed reading my article and were able to understand the concept thoroughly. If you have any doubt regarding the concept you can mail me at my email is : shivam234agarwal@gmail.com .  In the last I would like to wish you luck for your board exams and have fun reading articles on High School Pedia.

Other articles on High School Pedia


Enjoy your high school with - High School Pedia : www.highschoolpedia.com


Comments

Popular Posts

Anode Ray Experiment

→Anode ray experiment was conducted by E Goldstein.

→These rays are also known as canal rays.

→This experiment helped in the discovery of the proton.


Apparatus Used A discharge tube was taken in which there were 2 electrodes i.e. Anode(+ve) and the cathode (-ve).The tube was filled with an inert gas.A perforated or porous cathode was used.
A layer of zinc sulphide was placed at the back of the cathode.There was a vacuum pump in the tube.High voltage (5000v-10000v) was allowed to flow through the system.It was observed that when the gas was at 1atm(atmospheric pressure) no change was seen in the tube. When thepressurewas decreased inside the tube, a glow could be seen at the back side of the cathode.

Android Versions Named After Sweet

Have you ever thought why are Android versions always named after sweet names ??

Everytime a new Android version is launched its name is kept after a sweet name. Many people have researched about this topic and many have asked Google also. Have you ever tried to find out the core reason behind this? If not then you would find the answer here .

First of all let us first see what Google says about this :

In 2008 i.e. the year when Android was launched a reporter asked the reason for the same. At that time Google said

“It’s kind of like an internal team thing, and we prefer to be a little bit — how should I say — a bit inscrutable in the matter, I’ll say,” said Randall Sarafa, a Google spokesman. “The obvious thing is that, yeah, the Android platform releases, they go by dessert names and by alphabetical order for the most part."



Rutherford Alpha Ray Scattering Experiment

Rutherford Alpha Ray Scattering Experiment
Hey, Guys, most of you might have heard about the alpha ray scattering experiment and if you want to know in detail about Rutherford's model and the experiment he conducted, this is the right place for you... But first:

Things You Must KnowSome basic information that will help you understand rutherford experiment properly: Proton is a sub-atomic particle which is positively charged and has a mass of 1u.Alpha particles are helium atom with a charge of +2 as they have lost 2 electrons.Alpha particles have an atomic mass of 4u.Gold is highly malleable and can be beaten into very thin sheets.



Experiment Rutherford conducted his experiment in the following way: Rutherford took a very thin gold foil and bombarded it with high energy alpha particles.He placed a layer of zinc sulphide on the walls where the experiment was taking place because when alpha particles strike zinc sulphide layer, it results in illumination. This helped to determine the path …

Pokemon Go 0.33.0

All Pokemon go fans get ready because again the latest version of Pokemon go is out. The Niantic has released a new version of Pokemon go i.e. 0.33.0.The size of the new version is 61.48MB.


SETS, RELATIONS & FUNCTIONS

SETS, RELATIONS & FUNCTIONSSets are a fundamental part of mathematics and it’s knowledge is very important in present. It defines the concepts of relation and functions. These functions are also very essential for present day maths. SETSSets are denoted by capital letters. They are similar to matrices whose elements are denoted by small letters. But in sets an element comes only at once. Sets are matrices which give a sense of belonging. This sense of belongingness is represented by ∈ .We can write anything in a set like rivers of India, Wonders of the World .etc.  For an example let there be a set of positive single digit. Let the set be denoted as A Therefore, 8 ∈ A  Also we can write, 17 ∈ A Set can be represented by two types  ROSTERIn roster form we write elements in curly brackets and separate them with comma.  If there be set of positive integers less than 10. Therefore the set will be {1,2,3,4,5,6,7,8,9}  SET- BUILDER FORMIn set-builder form we take a variable x and then gives its…

Isotopes, Isobars and Isotones

Isotopes

These are elements which have the same atomic number but different atomic mass.They have the same atomic number because the number of protons that are inside their nuclei remains the same.But, they have different atomic mass because the number of neutrons that are also inside their nuclei is different.As the number of protons inside nuclei remains same, therefore the overall charge of the elements also remains same as in isotopes: no of protons = no of electrons.Hence, as isotopes overall charge remains neutral, therefore their chemical properties will also remain identical.Therefore, Isotopes are chemically same but physically different.

Cathode Ray Experiment

This experiment was conducted by J.J. Thomson (Sir Joseph John Thomson) in the year 1897.This experiment proved that atom is made up of fundamental particles which are much smaller than the smallest atom 'hydrogen'This experiment helped to discover electron.According to J.J. Thomson, the cathode rays consisted of very light, small and negatively charged particles.He named the particles "corpuscles" which were later known as electrons