Asked/Added Questions From NCERT: Mathematics

  Let ABCD, the square garden of side= 30 m.

PQRS is the region inside the garden.

so,

PQ = (30 -1-1 ) = 28 m

also

PS = ( 30 – 1 – 1 ) = 28 m 

(i) Area of the path = Area of ABCD – Area of PQRS 

= [( 30 x 30) – (28 x 28)]

= 900 – 784 

= 116 sq.m 

(ii) Area of the remaining portion in which the grass is planted = Area of square PQRS 

= 28 x 28 

= 784 sq.m 

cost of planting the grass in the region PQRS =  area x cost = 764 x 40

 =31,360

-Answered by Himanshi Verma On 17 January 2019:05:24:42 PM

 An integer that is divisible by 2 is called Even Number.

-Answered by Himanshi Verma On 17 January 2019:05:28:03 PM

 Counting numbers are numbers you can use to count whole items. You can use the positive integers to count marbles, for example. Whether 0 is a counting number or not, that's a big debate you may or may not be interested in 

-Answered by Harshita Rathore On 17 January 2019:05:31:45 PM

 ( a² - b² )³ + ( b² - c² )³ + ( c² - a² )³ ] / [ ( a - b )³ + ( b - c )³ + ( c - a )³ ] == 3( a² - b² )( b² - c² )( c² - a² ) / 3( a - b )( b - c )( c - a ) ... In triangle abc, p is the midpoint of seg ab.

-Answered by Nitish kumar On 17 January 2019:10:36:38 AM

 1

-Answered by Himanshi Verma On 17 January 2019:05:27:08 PM

 The Hindu-Arabic numerals are the ten digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). They are descended from Indian numerals, and the Hindu-Arabic numeral system by which a sequence of digits such as "406" is read as a whole number was developed by Indian mathematicians.

-Answered by Himanshi Verma On 17 January 2019:05:27:36 PM

  Lateral Surface Area of cube=256 cm²

-Answered by Himanshi Verma On 16 January 2019:06:04:58 PM

  Total surface area of cube is 150sq. cm

Total surface area of cube : 6a²

^{To find perimeter of its one faces :  ?}

Total surface area of cube =150sq.cm

                           6a²  =150sq.cm

 = 1506 

= 25cm

=a² = √25cm

=a = 5 cm

Perimeter of its one face is = 4 × a

                                        = 4 × 5 cm

                                        = 20 cm Answer

-Answered by Akki chauhan On 16 January 2019:10:09:26 AM

  Ans 1. Zero(0)

Ans 2. 0 and 1

Ans 3. 2

-Answered by Akki chauhan On 15 January 2019:09:06:44 AM

   l=10cm r=8cm

The total surface area of cone=πr(l+r)

                                          =22/7×8(10+8)

                                          =22/7×8(18)

                                          =22/7×144

                                          =3168/7cm

-Answered by Akki chauhan On 15 January 2019:09:06:10 AM

 The concentric circle are the circles with a common center the region between two concentric circle of different radii is called an annulus. 

-Answered by Akki chauhan On 15 January 2019:09:05:48 AM

 √125 +2√27 +(-5√5 -√3)

=√5×5×5 +2√3×3×3 -5√5 -√3 

=5√5 +6√3 -5√5 -√3

=5√3

-Answered by Akki chauhan On 15 January 2019:09:05:29 AM

  ∠A + ∠C = 180 ....1

But ∠A = ∠C

So ∠A = ∠C = 90

Again 

  ∠B + ∠D = 180 ....2

But ∠B = ∠D

So ∠B = ∠D = 90

Now each angle of parallelogram ABCD is 90.

Hense ABCD is a rectangle

-Answered by Akki chauhan On 15 January 2019:09:05:05 AM

 2x-5=0

2x=5

x= 5/2

-Answered by Akki chauhan On 15 January 2019:09:04:26 AM

  x³ -23x²+142x-120 

=x³-x²-22x²+22x+120-120

=x²(x-1)-22x(x-1)+120(x-1)

=(x-1)(x²-22x+120)

=(x-1)(x²-12x-10x+120)

=(x-1)[x(x-12)-10(x-12)]

=(x-1)(x-10)(x-12)

-Answered by Himanshi Verma On 16 January 2019:05:57:48 PM

 The first 10 prime numbers are : 2,3,5,7,11,13,17,19,23 and 29.

n=10

Median if n is even numbers

n2 th term = 5th term = 11

n2 + 1 = 5 + 1 = 6th term = 13

Median = 5th term + 6th term2 

Median = 11 + 132 

 = 242 = 12 Answer

-Answered by Akki chauhan On 15 January 2019:09:03:48 AM

 The number of times an observation occurs in the given data is called frequency of the observation.

-Answered by Rohit Rajput On 12 January 2019:08:59:05 AM

 Highest power of x in the algebraic expression is called the degree of the polynomials.

-Answered by Prince Rawat On 11 January 2019:10:08:00 AM

Given : In a circle C(O,r) , ∠AOB = ∠COD 

To Prove : Chord AB = Chord CD .

Proof : In △AOB and △COD 

AO = CO [radii of same circle]

BO = DO [radii of same circle]

∠AOB = ∠COD  [given]

⇒  △AOB ≅  △COD [by SAS congruence axiom]

⇒   Chord AB = Chord CD [c.p.c.t]

-Answered by Akki chauhan On 13 January 2019:01:04:33 PM

  Start with: -20 = -20

-Answered by Akki chauhan On 15 January 2019:09:03:13 AM

  21b - 32 + 7b - 20b

=(21b+7b -20b) - 32

=8b - 32 Answer

-Answered by Akki chauhan On 10 January 2019:10:54:03 AM

 3p²q² - 4pq + 5 + (-10p²q²) + 15 + 9pq + 7p²q² 

= 3p²q² + 7p²q² - 10p²q² + 9pq - 4pq + 5 + 15 

= 10p²q² - 10p²q² + 5pq + 20 

= 5pq + 20 Answer

-Answered by Akki chauhan On 10 January 2019:10:54:27 AM

 x+7+4(x-5)=2

x+7+4x-20=2

5x-13=2

5x=2+13

5x=15 

x=3

So, The value of x is 3. 

-Answered by Akki chauhan On 14 January 2019:10:15:24 AM

   Mean is an average of some data which is calculated by dividing ∑Sum of data by total numbers of data

-

-Answered by Rohit Rajput On 11 January 2019:09:59:24 AM

    x² + 2x + 1 

= x² + x + x + 1

= x(x + 1) + 1(x + 1) 

= (x + 1) (x + 1) 

-Answered by Akki chauhan On 10 January 2019:10:57:10 AM

 For finding the value of x first we find mean of 5, 10, 3 

sum of observation = 5 + 10 + 3 = 18

mean = 18 / 3 = 6 

Therefore, x = 6 

Now we have data for median 11, 12, 14, 18, 21, 23 

n = 6 { n is an even number} 

n/2 th trem = 14 

and (n/2 + 1)th trem = 18 

Median = (14 + 18)/2 = 32/ 2 = 16 Answer

-Answered by Akki chauhan On 14 January 2019:10:14:53 AM

 S7 = 7/2(2a + 6d) 

=> 49 = 7a + 21d

=> 7 = a + 3d   ------------ (i) 

S17 = 17/2 (2a + 16d) 

=> 289 = 17a + 136

=> 17 = a + 8d --------------  (ii) 

Substracting equation (i) from (ii) 

we have ... 

17 - 7 = a - a + 8d - 3d 

10 = 5d 

d = 10/5 

d = 2 

Putting the value in Equation (i) 

7 = a + 3d 

7 = a + 3 x 2 

a = 7 - 6 

a = 1 

Sum of first n terms = n/2 [2a + (n - 1) d]

= n/2 [2x 1 + (n - 1)2] 

= n/2 [2 + 2n - 2 ]

= n/2 (2n) 

= nxn = n2

-Answered by Akki chauhan On 14 January 2019:10:14:29 AM