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Time and Work


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Problem type -1
1-Rajan can do a piece of work in 24 days.  While Amit can do it in 30 days. In how many days can they complete it. If they work together. 
2- Kabita can finish a piece of work in 12 days and Babita alone can do it in 15 days. If both of them work at it together, how much time will they take to finish it?
3- Two motor mechanics shivam and gulshan working together can overhaul a scooter in 6 days. while Shivam alone can do the job in 15 days. In how many days can gulshan alone do it 

Problem type - 2
1- A can do a piece of work in 25 days and B can finish it in 20 days. They work together for 5 days and then A leaves. In how many days B finish the remaining work?
2- A , B and C together can do a piece of work in 6 days. A alone can do it in 12 days. B alone can do it in 30 days. in how many days C can finish the work

Problem type-3
1-A and B working together can finish a piece of work in 6 days. while A alone can do it in 9 days. how much time will B alone take to finish it?
2- three taps A, B and C can fill an overhead tank in 6 hours, 8 hours and 12 hours respectively. How long would the three taps take to fill the empty tank if all of them are opend together
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quadratic equation / chapter - 4 / class - 10 /Math / New St. Mery English School


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Topics to be covered 
1- Need to quadratic equations in real life.
2-Recap (polynomial, equation, zeroes of a polynomial, relation between zeros of a polynomial, splitting of terms, completing the square method, quadratic formula, linear equation word problem
3- what is quadratic equation?
4- standard form of quadratic equation
5- Roots / zeroes/ solutions/poles of a quadratic equation
6- solving a quadratic equation
       a- factorization method
       b- completing the square method
       c- quadratic formula (sidharacharya law )
7- Nature of roots
8-word problems involving quadratic equation 

1- Need to quadratic equations in real life.

 1-It is used in tackling real life situation in the form of world problems.
2- It is used in solving puzzles
3- It is used in sports
4- It is used in study parabolic shape made by football 

2-Recap

term - The part of an algebraic expression which is the combination of variable and constant combined with multiply sign is called term 

Ex:- 6xy2 , -4y2 , 2x , 7x3y3z3       

Algebraic expression- The group of terms combined with plus ( + ) or minus ( - ) sign is called algebraic expression.

Ex:- 5y2 + 2x – 3

             2x3 + 3x2 – 4x + 8

Polynomial- An algebraic expresson whose powers are non-negative integer is called polynomial

Ex:- 5y2 + 2x – 3

             2x3 + 3x2 – 4x + 8

 Degree of a Polynomial - The highest power of a polynomial is called the degree of that given polynomial.

Ex:- 5y2 + 2x – 3  |( Here the degree of polynomial is 2 )

             2x3 + 3x2 – 4x + 8  ( Here the degree of polynomial is 3 )

There are four types of polynomial on the basis of degree

1- linear polynomial

2- quadratic polynomial

3- cubic polynomial

4- by-quadratic polynomial

What is equation?

Ans:- An equation is formed when two polynomials are combined by equal to sign ( = )

 What is quadratic equation?

Ans:- An equation that is in the form of  'quadratic polynomial = 0' than that equation is called quadratic equation.

Ex:- 5y2 + 2x – 3 = 0

What is equation?

Ans:- An equation is formed when two polynomials are combined by equal to sign ( = )

 What is quadratic equation?

Ans:- An equation whose degree is 2 is called quadratic equation

                                                   or

An equation that is in the form of  'quadratic polynomial = 0' than that equation is called quadratic equation.

If p(x) is a quadratic polynomial than p(x) = 0 is a quadratic equation

 

 What is roots of the quadratic equation?

Ans:- Let p(x) = 0 is a quadratic equation, than the zeroes of the polynomials p(x) are called the roots of the equation p(x) = 0

or

variable का वह मान जिसे variable के स्थान पर रखने पर हमारा quadratic equation सटिस्फाय हो जाये तब वेरिएबल का वह मान ही roots of the quadratic polynomial कहलाता है 

therefore, x = ∝ is a root of p(x)=0, if and only if  p(∝) = 0


 


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Speed-distance-time / class - 4-5-6 /Math / New St. Mery English School


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Problem type - 1

1- Find the speed if distance = 45 km and time = 3 hours 

2- Find the speed if distance = 60 km and time = 4 hours

3- Find the speed if distance = 900 km and time = 18 hours

Problem type -2

1- if the distance covered by a bus is 250 km in 5 hours.Find the speed of the bus.

2- If the distance covered by a train is 424 km in 8 hours. Find the speed of a train.

3- find the speed of the bus which covers a distance of 600 km in12 hours.

4- If the distance covered by a car is 460 km in 10 hours. Find its speed.

5- If the distance covered by a train is 2500 km in 25 hours. Find its speed.

6- A boy can cover 25 km in 5 hours. find his speed.

Problem type -3

 1- If a train starting from New Delhi to Govindpur , covers a distance of 440 km in 5 hours and 30 minutes. What is the speed of train?

Problem type -4

1- A train starts from one city on thursday at 8:00 pm and reached in another city on saturday at 8:00 am. If the distance between the both cities is 1692 km, find the average speed of the train.

2- A motor car starts from a city A at 5:30 am and reaches city B 360 km away at 11:30 am. Find the average speed of the motor?

Problem type -5

1- Change 56 km/hr into m/s

2- Change 72 km/hr into m/s

3- Change 124 km/hr into m/s 

4- Change 90 km/hr into m/s 

Problem type -6

1- Express 35 metre / second into km / hr

2- Express 48 metre / second into km / hr

3- Express 800 metre / second into km / hr

Problem type -7

1- A bus travels at a speed of 45 km/hr. How much distance will it cover in 10 hours?

2- A  car travels at a speed of 60 km/hr. How much distance will it cover in 5 hours?

3-  A train runs at a speed of 125 km/hr. How much distance will it cover in 5 hours?

4- A bus travels at a speed of 65 km/hr. How much distance will it cover in 5 hours?

5- A train runs at a speed of 140 km/hr. How much distance will it cover in 7 hours?

Problem type -8

 1- A person travelling by a train crosses a tunnel in 4wholes 1/2 minutes. If the speed of train is 36 km/hr. Than find the length of tunnel.

2- A car traveling at the average speed of 50 km/hr. How much distance would it cover in 30 second.


Problem type -9

1- A train runs at a speed of 75 km/hr. How much time will it take to cover 225 km?

2- Mohit runs at a speed of 15 km/hr. How long time will he take to run 900 metre race?

3- Santosh runs at a speed of 10 km/hr. How long time will he take to run a 700 metre race?

4- A train runs at a speed of 14 km/ hr. How long will it take to cover a distance 280 km?

5- A car travels at a speed of 40 km/hr. How long time will it take to cover 160 km.

Problem type -10

 1- A 360 m long train is running at a speed of 45 km/hr. What time will it take to cross a 140m long bridge?

2- Mohan covers a distanceof 108 km at a speed of 15 m/sec by a car. How many hours will he take to cover this distance? 

Problem type -11

1- A train covers a distance of 140 km in 3 hours and 30 minutes. How much time would it take to cover a distance of 250 km running at the same speed.

Problem type -12

1- A train is running at 36 km/hr If it crosses a pole in 25 second. than find the length of train.

Problem type -13

1- A bus travels 38 km in first hour. 35 km in second hour. 52 km in third hour. and 35 km in last hour. Find the average speed of the bus in per hour


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Temperature / Class 4-5-6 / New St. Mery English School


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 Convert the temperatures given below to Fahrenheit scale

50℃

30℃

70℃

90℃

0℃

100℃

37℃

Convert the temperatures given below to celsius scale

87℉

122℉

90℉

97℉ 

32℉ 

98.6℉ 

212℉ 


 

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Round number / Class-4-5 / New St. Mery English School


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 Round each of the following numbers to the nearest ten

36

173

3869

16378

 Round each of the following numbers to the nearest hundred

814

1254

43126

98165

 Round each of the following numbers to the nearest thousand

793

4826

16719

28394

 Round each of the following numbers to the nearest ten thousand

17514

26340

34890

272685

Estimate each sum to the nearest ten

57 + 34

43 + 78

14 + 69

86 + 19

95 + 58

77 + 63

356 + 275

463 + 182

538 + 276

Estimate each sum to the nearest hundred

236 + 689

458 + 324

170 + 395

3289 + 4395

5130 + 1410

10083 + 29380

Estimate each sum to the nearest thousand

32836 + 16466

46703 + 11375

Estimate each difference to the nearest ten

53 - 18

97 - 38

409 - 148 

Estimate each difference to the nearest hundred

678 - 215

957 - 578

7258 - 2429

5612 - 3095

Estimate each difference to the nearest thousand

35863 - 27677

47005 - 39488


 

 


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linear equation in two variable / chapter 3 / class - 10 /Math / New St. Mery English School


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 What is an algebraic expression?

What are polynomials?

What is an equation?

Ans:- Two algebraic expressions or two polynomials that are combined with equal sign is called equation.

Ex:- 5xy + 9 = 3x + 4y 

What is an inequation?

Ans:- Two algebraic expressions or two polynomials that are combined with greater or  smaller sign is called inequation.

Ex:- 5xy + 9 > 3x + 4y,    5y - 6<2xy

What is a linear equation?

Ans:- An equation which have one and only one type of  variable in each term and each term has degree one is called linear equation.

What is linear equation in one variable?

Ans:- An equation that is in the form of ax + b = 0, where a ≠ 0 is called linear equation in one variable.

The standard form of linear polynomial is ax + b = 0

What is linear equation in two variable?

Ans:- An equation that is in the form of ax + by + c = 0 where a ≠ 0 and b ≠ 0 is called linear equation in two variable.

The standard form of linear polynomial in two variable is ax + by + c = 0

At a time one and only one coefficient of linear polynomial in two variable becomes zero.

If a = 0 than  b ≠ 0

If b = 0 than a ≠ 0


What is solution?

Ans:- Variable का वह मान जिसे equation मे variable के स्थान पर रखने पर equation के LHS का मान equation के RHS के मान के बराबर हो जाये , तो variable के उस मान को solution कहते हैं। 

👉 linear equation का एक  solution होता है। 

What is solution of a linear equation in two variables?

Ans:- x = ∝  and y = β is a solution of ax +by + c = 0, if  a∝ +bβ + c = 0

or

The value of x and y that satisfies the equation is called the solution of a linear equation in two variables.

Ex:- x + y = 8

x = 1, y = 7 is a solution of given equation 

x = 2, y = 6 is a solution of given equation 

x = 6, y = 2 is a solution of given equation 

x = 7, y = 1 is a solution of given equation 

x = 5, y = 3 is a solution of given equation 

Note:- There are infinite solutions of linear equation in two variable

What are simultaneous of linear equations in two variables?

Or

What are pair of linear equations in two variables?

Or

What are system of linear equations in two variables?

Ans:- Two linear equations in two unknowns are said to form a system of simultaneous linear equations if we analyse them together and the variables used in both the equations are same. 

Ex:- x + y = 10

       x - y = 1

Standard unit of  system of linear equations in two variables is

a1x + b1y + c1 = 0

a2x + b2y + c2 = 0

 

What is solution of a system of two simultaneous linear equations?

Ans:- A pair of values of the variables x and y satisfying both of the equations in a given system of 2 simultaneous linear equations than x and y is called a solution of the system of linear equations.


Note:- There are unique solution or infinite solutions or no solutionof pair of linear equations  in two variable

How many types of pair of linear equations  in two variable on the basis of solution?

Ans:- There are two types of pair of linear equations  in two variable on the basis of solution.

1- consistent system

2- in-consistent system

What is consistent system pair of linear equations  in two variable?

Ans:- A pair of linear equations which consists at least one solution is called consistent system pair of linear equations  in two variable.  

What is in-consistent system pair of linear equations  in two variable?

Ans:- A pair of linear equations which consists no solution is called in-consistent system pair of linear equations  in two variable.  

Graphical representation of pair of liner equation in two variable ( Nature of solution )

The two lines that are drawn through pair of linear equations in two variable and both lines have a common point. These type of equations have unique solution. It is also called consistent system

The two lines that are drawn through pair of linear equations in two variable and both lines have infinite common points. These type of equations have infinite solutions. It is also called consistent system

The two lines that are drawn through pair of linear equations in two variable and both lines are parallel to each other. These type of equations have no solution. It is also called in-consistent system

Standard unit of  system of linear equations in two variables is

a1x + b1y + c1 = 0

a2x + b2y + c2 = 0

if ratio of  a1 / a2 ≠  ratio of  b1 / b2 than they have unique  solution

Its converse is also true.

if  a1 / a2 =  b1 / b2 = c1 / c2   than they have infinite  solution.

Its converse is also true. 

if  a1 / a2 =  b1 / b2  ≠  c1 / c2   than they have no  solution.

Its converse is also true. 

कैसे हम बतलाएंगे की linear equation in two variables से खींची जाने वाली लाइन x-axis और y-axis को कहाँ पर काटेगा 

Ans:- 

step 1- equation को  ax + by = c के form में लिख लें 

step 2- c हमेसा +ve होना चाहिए 

step 3- अब x के coefficient का symbol और y के coefficient का symbolबतलाएगा की linear equation in two variables से खींची जाने वाली लाइन x-axis और y-axis को कहाँ पर काटेगा 

कैसे हम बतलाएंगे की linear equation in two variables से खींची जाने वाली लाइन origin से होकर गुजरेगा ?

Ans:- यदि equation में c का value जीरो  हो , तब linear equation in two variables से खींची जाने वाली लाइन origin से होकर गुजरेगा 

ALGEBRAIC METHODS OF SOLVING SIMULTANEOUS LINEAR EQUATIONS IN TWO VARIABLES:

There are three common methods that are used to solve simultaneous linear equations in two variable by algebraic method.

1- Method of elimination by substitution (or) substitution method

2- Method of elimination by equating the coefficients ( or ) elimination method

3- Method of cross multiplication 

Method of elimination by substitution (or) substitution method 

In this method , we express one of the variables in terms of the other variable from either of the two equations and then this expression is put in the other equation to obtain an equation in one variable .

For solving simultaneous linear equations in two variable by Method of elimination by substitution (or) substitution method, We should follow the following steps.

Step1:- Express Y in terms of X in one of the given equation.

Step2:- Substitute this value of Y in term of X in the other equation. This gives a linear equation in X\

Steo3:- solve the linear equation in X. obtain the value of X

Step4:- Substitute this value of X in the relation taken in step 1 to obtain a linear equation in Y.

Step5:- Solve the above linear equation in Y to get the value of Y     

Method of elimination by equating the coefficients ( or ) elimination method

 

In this method eliminate one of the 2 variables to obtain an equation in one variable which can be solved easily. Now put the value of this variable in any one of the given equation, The value of the other variable can be obtained 

For solving simultaneous linear equations in two variable by Method of elimination by equating the coefficients elimination method, We should follow the following steps.

Step1:- multiply the given equation by suitable numbers so as to make the coefficients of one of the unknown variables numerically equal.

step2- If the numerically equal coefficients are opposite in sign then add the new equation. otherwise subtract them.

step3- resulting equation is linear in one unknown variable.

step4- Substitute this value in any of the given equations.

Step5- Solve it to get the value of the other unknown variable.

Step3-