Class 6 ,Math, Amv 2079

Which is inCorrect?

• Subtract 5a-4b from 8a- 3b=(8a-3b)-(5a-4b)=8a-3b-5a+4b=8a-5a+4b-3b=3a+b+z

• Add (4x+6y) and (-2x -5y)=(4x+6y)+(-2x-5y)=4x+6y-2x-5y=4x-2x+6y-5y=2x +y

• Multiply (a+2b)and4c=(a+2b)x4c=4ac+8bc

• Divide4ab by 2a=4ab÷2a=2b

which is wrong?

• -6<-4

• 0>-1

• 6-2=4

• 4>5

Which is incorrect?

• If A={1,2,3} n(A)=3

• if B={ },n(B)= 0

• if C={a,b},n(C)=2

• if D={1,6,8,90} n(D)=5

Which is correct?

• P={1,2,3,5,7,11,13} .it is set of prime number less than 14.

• Q={4,6,8,8,9,10}its Description form is

  Q={ set of composite number less than 11}

• S={1,4,9,16,25,36,49,64,81,100}its description form is

  S={ set of square number from 1 to 100}

• C={1,8,27,64,125}it's set builder form is

  C={x:x is cube number ,x < 126}

• E={2,4,6,8,10}it's in Listing Method .

which is incorrect?

• A set can be represented in three ways:

  i)Description Method .Example:A is set of Counting numbers less than 10.

  ii)Tabulation/Listing/Roster Method .Example:A={1,2,3,...9}

  iii)Set builder Method. Example:A={x:x is Counting numbers less than 10}

• Total number of elements in a set is the Cardinal of set .

  A={2,3,4,8,9}, n(A)=5

• B={x:x is a prime number less than 10} ={2,3,5,7},n(A)=4

• C={Set of vowels in English alhabets}={a,e,i,o,u}. so, n(C)= 5

• D={7,8,9} ,N(D)=24

If A = { 2,3,5}, B = { 2,4,6} , are sets A and B equivalent and overlapping sets ?  Which are incorrect?

• set A and set B are disjoint sets as well as equivalent sets

Which is incorrect?

• Subtract 5a+7 from 8a-6=(8a-6)-(5a+7)=8a-6-5a-7=8a-5a-6-7=3a-13

• Add:(4x+5y)+(-3x-2y)=4x+5y-3x-2y=4x-3x+5y-2y=x+3y

• Add:(4x+5y)+(-3x-2y)=4x+5y-3x-2y=4x-3x+5y-2y=x+3

• Subtract 5a+7c from 8a-6c=(8a-6c)-(5a+7c)=8a-6c-5a-7c=8a-5a-6c-7c=3a-13c

• Subtract -5a-7c from -8a-6c=(-8a-6c)-(-5a-7c)=-8a-6c+5a+7c=-8a+5a-6c+7c=-3a+c

Which is incorrect?

• $AB\parallel DC,AD\parallel BC,EF\parallel HG,EH\parallel HG$ AB is parallel to DC ,(AB // DC )

• $AB\ \perp\ AD\ ,\ AD\ \perp DC\ ,AE\perp EH\ \ ,DH\perp EH$ AB is perpendicular to AD (AB $\perp$ AD)

• above figure is rectangle.

• V= l x b x h

Which is incorrect?

• What is H.C.F of 24 and 40 by prime factor Method .

  Solution: 24= 2 x 2 x 2 x 3

  40= 2 x 2 x 2 x 5

  H.C.F = 2 x 2 x 2 = 8

• Find H.C. F of 12 and 18 by factor method .

  Solution : Factor of 12 (F₁₂)= { 1,2,3,4,6,12}

  Factor of 12 (F₂₄) = { 1,2,3,4,6,8,12,24}

  Common factor of 12 and 24 = {1,2,3,4,6,12}

  Highest common factor of 12 and 24 = {12}

  H.C.F = 12

• Find H.C. F of 12 and 18 by division method

  Solution : 12 ) 18 ( 1

  - 12

  .................

  6 ) 12 ( 2

  - 12 So , H.C.F = 6

  ...................

  x

• Find H.C. F of 2 and 3

  Solution : H.C.F of 2 and 3 = 2 x3 =6

• Find H.C. F of 2 and 3

  Solution : H.C.F of 2 and 3 = 1

which is incorrect ?

• Find the L.C.M of 6 and 8 by factor method .

  Solution : 6 = 2 x 3

  8 = 2 x 2 x 2

  L. C . M = 2 X 2 X 2 X 3 = 24

• Find the L.C.M of 6 and 8 by multiple method .

  Solution : Multiples of 6( M₆ ) = { 6,12,18,24,30,36 ,42, 48,..., }

  Multiples of 8 (M₈) = { 8 ,16, 24 ,32, 40 , 48 ,....,.}

  Common Multiples of 6 and 8 = { 24 , 48 ,....}

  Least Common Multiple of 6 and 8 = { 24}

  L.C.M = 24

• Find the L.C.M of 6 and 8

  Solution : 6 and 8 = 2