Let the number of terms required to make the sum of 636 be n and common difference be d.

Given Arithmetic Progression : 9 , 17 , 25 ....


First term = a = 9

Second term = a + d = 17

Common difference = d = a + d - a = 17 - 9 = 8



From the indentities of arithmetic progressions, we know : -
, where  is the sum of first term to nth term of the AP, a is the first term, d is the common difference and n is the number of terms of AP.

In the given Question, sum of APs is 636.


Therefore,


= > 4n² + 5n - 636 = 0

= > 4n² + ( 53 - 48 )n - 636 = 0

= > 4n² + 53n - 48n - 636 = 0

= > 4n² - 48n + 53n - 636 = 0

= > 4n( n - 12 ) + 53( n - 12 ) = 0

= > ( n - 12 )( 4n + 53 ) = 0


By Zero Product Rule,

= > n - 12 = 0

= > n = 12



Hence,
Number of terms of the AP [ 9 , 17 , 25 ] which are required to make the sum of 636 is 12.

One such compound is benzene. In benzene, six carbon atoms form a ring structure and there are three single and three double bonds between the carbon atoms. We can draw the structure of benzene as: Hence, benzene can be taken as an example of a cyclic unsaturated carbon compound.

Water is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients

Circulatory System: The circulatory system is responsible for transport of various substances in human beings. It is composed of the heart, arteries, veins and blood capillaries. Blood plays the role of the carrier of substances.

To mark the “Harela” festival of Uttarakhand, Red Fort International Public School organised an online campaign, through which students were encouraged to plant a sapling in or around their homes and take a selfie to post it on to the school.

This was initiated to create awareness among the students to take care of the environment. The students were instructed not only to plant trees but also to conserve trees in their surrounding.

The school organised a tree plantation drive in the school campus along with Chairman– Mr. Shurvir Singh Bisht, Principal– Dr. Manoranjan Devrani, Vice Principal– Mrs. Kalpana Sharma, Academic Head– Mr. Amit Mamgain, Mr. Manoj Bisht, other staff members- Co-ordinator– Mr. Devendra Bisht, Ms. Sony, Mr. Manoj Rawat, Mrs. Shweta, Mr. Yash Raj Tayal

Relationship--- Friendship? 

▪ Mr. Lamb’s positivity, attitude towards life, optimism, maturity, explaining with examples, persistence towards Derek---accepting of Derek will all his imperfections— calls him a friend ---said there were friends everywhere— explains saying they aren’t enemies 

▪ Derek gradually opens up---finds his company appealing -- --Derek argues---his condition has made him bitter--- people’s behaviour and treatment ---believes if he becomes Mr. Lamb’s friend, others might stop considering him their friend----his words have an impact---he overcomes issues holding him back 

(NOTE--Conclusion important) ---Even though Derek did not affirm out loud, the fact that Mr. Lamb’s words inspired trust enough to help him open up ----also got back to Mr. Lamb’s garden—overcame his own challenges---recognised Mr. Lamb’s impact---- Was a bond they shared—can call it friendship. 

Ancient stories of Mesopotamia are valuable sources of information. As per the stories, Mesopotamia is situated between two rivers, the Tigris and Euphrates. Mesopotamia was one of the advanced civilizations of its time. Its society was divided into three classes, i.e.

1. The upper class
2. The middle class and
3. The lower class

People belonging to upper classes led a life full of comforts and luxury and enjoyed special privileges. Agriculture was the main occupation of the people. Their life was normally prosperous. Religion was an important part of their life and people worshiped many gods and goddesses. Shamas was their main God. It was the Sun. Ziggurat was the name given to Sumerian temples.

Another description from the Bible: According to the Bible, the flood was meant to destroy all forms of life on the earth. However, God chose a man, Noah, to ensure that life could continue after devastating flood on the earth. Noah, built a huge boat, an ark. He took a pair each of all known species of animals and birds on the board, the arks which survived the flood. When other things were destroyed by the flood, his boat remained safe along with all the species. Thus began a new life on the earth. There was a similar striking story in Mesopotamian tradition, where the principal character was called Ziusudra or Utnapishtim.

A N S W E R
We can not see clearly through fog because the light is scattered by the droplets in the fog. The light is scattered by very small particles, this phenomenon is called Tyndall effect.

CPU – Central Processing Unit.

VDU - Stands for "Visual Display Unit."

Brownian movement may be defined as continuous zigzag movement of the colloidal particles in a colloidal solution. It depends on the size of the particles and the viscosity of the colloid. Smaller the size of the particle and lesser its viscosity, faster is its motion. This movement is responsible for the stability of sols

Food Preservatives

• Food preservatives prevent spoilage of food due to microbial growth. The most commonly used preservatives include table salt, sugar, vegetable oils and sodium benzoate, C₆H₅COONa.
• Sodium benzoate is used in limited quantities and is metabolised in the body. Salts of sorbic acid and propanoic acid are also used as preservatives.

Materials which allow light to pass through them completely are called Transparent objects. Objects on the other side of Transparent objects can be seen clearly. Eg: Glass, water and air.

Collection of all positive and negative numbers including zero are called integers. ⇒ Numbers …, – 4, – 3, – 2, – 1, 0, 1, 2, 3, 4, … are integers.

Federalism is needed to provide consistency between all the states and provinces of a country. If you have inconsistent rules across a nation, you will have many situations where different people act in an identical manner, but act illegally in one state, and legally in the next. 

Businesses and foreign visitors want consistency in rules. They want to know what they have to comply with everywhere in a country. Differing state rules will discourage foreign investment and slow down an economy. 

In the U.S., rules are much more consistent between states. Businesses know basically what to comply with across the country, and therefore, investment is consistent across the country.

Human resources are important because the development of other resources solely depends upon this resource as humans have knowledge, skill, and technology to develop other resources.

Below you will get a link to download the official books and Notes from CBSE for Class 10 IT CODE 402 2021. These notes and books provided below are official and the link is also official. You can download it with a single click this will surely help you in the preparation of your examination.

<a href="http://www.cbseacademic.nic.in/web_material/Curriculum21/publication/secondary/Employability_Skills10.pdf">Employability Skills Class 10 Book PDF by CBSE ( Download Now )</a>

<a href="http://www.cbseacademic.nic.in/web_material/Curriculum21/publication/secondary/X_Emplobility_Skills_Combined_book.pdf">Employability Skills Class 10 Notes PDF by CBSE ( Download Now )</a>

<a href="http://cbseacademic.nic.in/web_material/Curriculum21/publication/secondary/402-IT_ClassX.pdf">IT Code 402 Class 10 Book PDF 2020-21 By CBSE (Download Now)</a>

The peculiar features of Nazi thinking were:

• A belief in racial hierarchy and Lebensraum or living space.
• Nordic German Aryans were at the top, while the Jews formed the lowest rung of the racial ladder.
• They believed that only the strongest race would survive and rule. This was borrowed from Darwin's theory of natural selection.
•  New territories must be gained for enhancing the natural resources and power of Germany.

The Indian society  was trapped in absurd customs like Sati,  Slavery ,female foeticide centuries., ignorance, superstitious beliefs , discrimination through caste system etc which were the hurdles for it's development and also were the bigger causes for its colonisation by Britishers .The enlightenment in the latter years gave birth to mass awakening against the British oppression and evil customs.To clean Indian society from every ignorance the social reformers started various movements in India.