Skip to main content


True Discount and Banker's Discount problems tricks in Hindi | fast track formulae for problem solving.


TRUE DISCOUNT 1). वास्तविक बट्टा = मिश्रधन - वर्तमान धन
2). यदि ब्याज की दर r% वार्षिक , समय t व वर्तमान धन (pw) है, तो वास्तविक बट्टा = PW×r×t/100
3). यदि r% तथा समय t के बाद देय धन A है, तो तत्काल धन pw = 100×A/(100+r.t)
4). यदि देय धन A पर r% व समय t दिए गए है, तो वास्तविक बट्टा = A.r.t /(100+r.t)
5). यदि किसी निश्चित समय के पश्चात निश्चित वार्षिक दर पर, देय धन पर वास्तविक बट्टा (TD) व समान समय व दर के लिए साधारण ब्याज (SI) हैं, तो देय धन A =      SI × TD/(SI - TD)
6). यदि t समय पश्चात r% वार्षिक दर पर, देय धन पर वास्तविक बट्टा (TD) व साधारण ब्याज (SI) है , तो -  SI - TD = TD×r×t/100
7). t वर्ष बाद r% चक्रवृद्धि दर पर देय धन A का तत्काल धन (PW) = A/(1+r/100)^t   व वास्तविक बट्टा = A - PW
BANKER'S DISCOUNT1). महाजनी बट्टा = शेष समय (समाप्त न हुए समय) के लिए बिल पर ब्याज = बिल की राशि × दर × शेष समय /100
2). महाजनी लाभ = महाजनी बट्टा - वास्तविक बट्टा
3). यदि बिल का मान / अंकित मूल्य A है, समय t व दर r% है, तो महाजनी बट्टा = A×r×t/100

The ultimate arithmetic formulae on PERCENTAGE for all competitive examination//

In "laws of nature" today we are going to talk about the some important arithmetic formulae on PERCENTAGE, which may be very helpful to you , in all types of competitive examination.

Some important sutras

* If two values are respectively x% and y% more than the third value,then the first is the = (100+x/100+y)×100%
of the second.

* If the two values are respectively x% and y% more than the third value,then second is the=(100+y/100+x)×100% of the first.

* If the two values are respectively x% and y% less than the third value,then the second is the= (100-y/100-x)×100% of the first.

* If the two values are respectively x% and y% less than the third value,then the first is the=(100-x/100-y)×100% of the second.

* If A is x% of C and B is y% of C then A is =x/y×100% of B

* If x% of quantity is taken by the first,y% of remaining is taken by the second and z% of remaining is taken by the third person,now if ₹A is left in the fund, then the fund was in the beginning=

* If A is the initial amount in the fund and x% is taken by the first ,y% is taken by the second and z% is taken by the third person then amount left in the fund is =

* If intial amount is A, then x% of initial amount is added to initial amount,then y% of increased amount is added to the amount,and then z% of increased amount added then initial amount become =

* If the original population of a town is P and annual increase is r% then the population after n years will be=

* If the present population of a town is P,and annual increase is r% then the population was n years ago will be=P/(1+r/100)^n

* If the original population of a town is P, and annual decrease is r% then population after n years will be=P(1-r/100)^n

* If the annual decrease in the population of a town is r%,and present population is P,then population of the town in n years ago will be=P/(1-r/100)^n

* The population of a city is P,it increases/decrease by x% in first year,y% in second year and z% in third years.then the population after the three years will be=

* If the population of a town is increase/decrease by x% in first year,y% in second year and z% in third year,and after the three years the population of town is to be noted P then the population of town in the beginning is =

* If the population of town is P1,and in the town male increased by x% and females increased by y% then the population become P2, then the no. Of males and females in the town is given as below=
 [P2×100-P1(100+y)]/(x-y) is the no of males
 [P2×100-P1(100+x)]/(y-x) is the no of females

* If the value is decreased/decreased successively x% and y% then the net decrease is as follows=[+-x+-y-(+-x)(+-y)/100]

* If one number is decreased/increased by x% and second number is decreased/increased by y% then the effect on the product is =[x+y-+(xy/100)]%

* The passing marks in a examination is x% and a student secures y marks and he fail by z marks,then the maximum marks of examination is =100(y+z)/x

* A student scores x% marks,and fails by a marks,another student who has scored y% marks and he get b marks more than the minimum required marks to be pass, then max marks of the examination is =

* In a examination x% fails in physics, y% failed in cosmology and z% students failed in both the subjects, then % of students who has passed the both exams is =100-(x+y-z)

* A man spends x% of his income, his income is increased by y% and his expenditure also increased by z% then the % increased in his savings is =

* If x% of objects is one type,the remaining y% is of second type, and remaining z% is third type, and the value of remaining objects is A then the total no of objects is =

* The producer of a goods makes a profit/loss of x% , whole seller makes the profit of y%, and retailer makes the profit of z%, if retailer sold it for RsA, then the producing cost of the goods is =

* In L litres of x% sulphuric acid solution,the amount of water to be added/removed to make the y% of acidic solution is =+-L(x-y)/y
  Note: here x% is always greater than y% if H2O is added,if H2O is removed then y is greater.

* Certain amount of solvent B is added to the solution of A and B of amount M to change the % amount of A to ∆A ,then amount of B to be added=[(A/∆A)×M]-M

* If the original value of a trust is A and new value is trust is B, then increase or decrease in the consumption such that the expenditure is unaffected.(B-A/B)×100%

* Splitting of a number N into two parts such that one part is x% of other, then the splitted two parts is=[100/(100+x)]×100 and

* If L litre of water is poured into a tank,but it is still x% empty then amount of water should be added to fill it up to brim=      L×x/(100-x) and capacity of tank is=100L/(100-x)

* If x%, y% and z% is successively three discount are given then a net single discount is=[x+y+z-(xy+yz+zx)/100+xyz/100]

*If x% houses contains two or more people and those houses which contains only one male is y% ,then % of all houses which contains exactly one female with no male is = [(100-x)(100-y)/100]

* If the monthly income of A is x% more than that of B, monthly income of B is y% less than that of C, if difference between the monthly income of A and C is M then the monthly income of B and C is =
[100M(100-y)/(100+x)(100-y)-100^2] and
[100^2M/(100+x)(100-y)-100^2] respectively

* Mass of two boys A and B is in the ratio of a:b ,if mass of A is increased by x% then the total mass become M, if mass of B is increased by y% then the total mass become=[(100+y)/100(1+a/b)-{a/b(100+x)/100+1}]×100%

*If a person spend x% of his monthly income on dance bar,and y% of remaining on worship, then after he saves Rs A, then the monthly income of the person is =
 Monthly amount spent on dance bar is =Ax×100/(100-x)(100-y)
Monthly amount spent on worship is=

* If r% is decreased in the value of a objects then a person buy A kg more objects in Rs x then the cost of the object is = rx/(100-r)A

* In the election of two candidates, one gets x% votes of total votes but lose by y votes, then the total no of votes is = 100y/(100-2x)

* In a examination between A boyes and B girls, r1% boyes pass and r2% girls get passed, then % of total passed students is =

* If the value of any object is increased by x% and then decreased by x%, then resultant is always get decreased then resultant is given as= x^2/100

* Convert x% in fraction = x/100
* Convert x% in decimal= 0.0x
* Convert X/y in percentage = (x/y)×100%
* If x% of A is equal to the y% of B, then z% of A is = (yz/x)×100%



Boat and stream short-tricks in Hindi | Fast track arithmetic formulae for competitive examination.

BOAT AND STREAM (नाव एवं धारा)
1). यदि शांत जल में नाव या तैराक की चाल x किमी/घंटा व धारा की चाल y किमी/घंटा है, तो धारा के अनुकूल नाव अथवा तैराक की चाल = (x+y) किमी/घंटा
2). धारा के प्रतिकूल नाव अथवा तैराक की चाल = (x-y) किमी /घंटा
3). नाव की चाल = (अनुप्रवाह चाल + उद्धर्वप्रवाह चाल)/2
4). धारा की चाल =  (अनुप्रवाह चाल - उद्धर्वप्रवाह चाल)/2
5). यदि धारा की चाल a किमी/घंटा है, तथा किसी नाव अथवा तैराक को उद्धर्वप्रवाह जाने में अनुप्रवाह जाने के समय का n गुना समय लगता है,(समान दूरी के लिए), तो शांत जल में नाव की चाल = a(n+1)/(n-1) किमी/घंटा
6). शांत जल में किसी नाव की चाल x किमी/घंटा व धारा की चाल y किमी/घंटा है, यदि नाव द्वारा एक स्थान से दूसरे स्थान तक आने व जाने में T समय लगता है, तो दोनो स्थानों के बीच की दूरी = T(x^2 - y^2)/2x km
7). कोई नाव अनुप्रवाह में कोई दूरी a घंटे में तय करती है, तथा वापस आने में b घंटे लेती है, यदि नाव कि चाल c किमी/घंटा है, तो शांत जल में नाव की चाल = c(a+b)/(b-a) km/h
8). यदि शांत जल में नाव की चाल a किमी/घंटा है, तथा वह b किमी/घंटा की चाल से बहती हुई नदी में गत…

Emergence of British East India Company as an Imperialist Political Power in India

Dynamically changing India during early eighteenth century had a substantially growing economy under the authority of Mughal emperor Aurangzeb. But after his demise in 1707, several Mughal governors established their control over many regional kingdoms by exerting their authority. By the second half of eighteen century, British East India Company emerged as a political power in India after deposing regional powers and dominating over Mughal rulers. The present article attempts to analyze the reasons for emergence of British East India Company as an imperial political power in India and their diplomatic policies of territorial expansion. In addition to this, I briefly highlighted the Charter Acts (1773, 1793, 1813, 1833 and 1853) to trace its impact on the working process of Company.Establishment of East India Company in India

In 1600, British East India Company received royal charter or exclusive license…

Three dimensional geometry (part-1) | study material for IIT JEE | concept booster , chapter highlights.


In the following diagram X'OX , Y'OY and Z'OZ are three mutually perpendicular lines , which intersect at point O. Then the point O is called origin.
In the above diagram X'OX is called the X axes, Y'OY is called the Y axes and Z'OZ is called the Z axes.
1). XOY is called the XY plane. 2). YOZ is called the YZ plane. 3). ZOX is called the ZX plane.
If all these three are taken together then it is called the coordinate planes. These coordinates planes divides the space into 8 parts and these parts are called octants.
COORDINATES  Let's take a any point P in the space. Draw PL , PM and PN perpendicularly to the XY, YZ and ZX planes, then
1). LP is called the X - coordinate of point P. 2). MP is called the Y - coordinate of point P. 3). NP is called the Z - coordinate of the point P.
When these three coordinates are taken together, then it is called coordinates of the point P.

A detailed unit conversion table in Hindi.

CENTIMETRE GRAM SECOND SYSTEM (CGS)1). MEASUREMENT OF LENGTH (लंबाई के माप) 10 millimeter = 1 centimetres10 centimetre = 1 decimetres  10 decimetre = 1 metres 10 metre = 1 decametres 10 decametres = 1 hectometres 10 hectometres = 1 kilometres 10 kilometres = 1 miriametresMEASUREMENTS OF AREAS ( क्षेत्रफल की माप )  100 millimetre sq. = 1 centimetre sq.
 100 centimetre sq. = 1 decimetres sq. 100 decimetres sq. = 1 metre sq. 100 metre sq. = 1 decametres sq  100 decametres sq. = 1 hectometres sq. 100 hectometres sq. = 1 kilometres sq. 100 kilometres sq. = 1 miriametres sq.
MEASUREMENTS OF VOLUME ( आयतन की माप) 1000 millimetre cube. = 1 centimetre cube.
 1000 centimetre cube. = 1 decimetres cube. 1000 decimetres cube. = 1 metre cube. 1000 metre cube. = 1 decametres cube. 1000 decametres cube. = 1 hectometres cube. 1000 hectometres cube. = 1 kilometres cube. 1000 kilometres cube. = 1 miriametres cube.
MEASUREMENTS OF VOLUME OF LIQUIDS  (द्रव्य के आयतन का माप) 10 millilitre=…

THE GENERAL THEORY OF RELATIVITY | A Unique way to explain gravitational phenomenon.

Today we are going to talk about a very important and revolutionary concept that is THE GENERAL THEORY OF RELATIVITY.
This theory came into existence after 10 years of special theory of relativity (1905), and published by Albert Einstein in 1915.
This theory generalise the special theory of relativity and refines the Newton's laws of universal gravitation.
After coming this theory people's perspective about space and time has been changed completely. And this theory give a new vision to understand the spacetime geometry.
This theory gives a unified description of gravity as a geometrical properties of space and time.
This theory helps us to explain some cosmological phenomenon that is ,

* why small planets revolve around the big stars?
* Why everything in this universe is keep moving?
* Why mostly planets and stars are spherical in shape?
* Why does gravity create?
* Why does time become slow near the higher gravitating mass. Ie. Gravitational time dilation.
And gravitational…