CBSE Class 6 Maths - Playing With Numbers - NCERT Exercise 3.6 (#cbsenotes)

Playing With Numbers

EXERCISE 3.6

CBSE Class 6 Maths

Q1: Find the HCF of the following numbers:
(a) 18, 48
(b) 30, 42
(c) 18, 60
(d) 27, 63
(e) 36, 84
(f) 34, 102
(g) 70, 105, 175
(h) 91, 112, 49
(i) 18, 54, 81
(j) 12, 45, 75

Answer:

(a) Factors of 18 = 2 × 3 × 3
Factors of 48 = 2 × 2 × 2 × 2 × 3
HCF (18, 48) = 2 × 3 = 6

(b) Factors of 30 = 2 × 3 × 5
Factors of 42 = 2 × 3 × 7
HCF (30, 42) = 2 × 3 = 6

(c) Factors of 18 = 2 × 3 × 3
Factors of 60 = 2 × 2 × 3 × 5
HCF (18, 60) = 2 × 3 = 6

CBSE Class 10 - Biology - Digestive Organs and Their Functions (#cbsenotes)

Digestive Organs and Their Functions

CBSE Class 10 - Physics - Electricity - Important Points To Remember (#cbsenotes)

Electricity - Important Points To Remember 

CBSE Class 10 - Physics 

① Electric current is defined as the amount of charge flowing through a particular cross section area in a unit time.


② The SI unit of electric current is ampere.


③ A stream of electrons moving through a conductor constitutes an electric current. In a conventional current, the direction of current is taken opposite to the direction of flow of electrons i.e. flow of positive charges from +ve terminal to -ve terminal.


④ 1 A is the flow of 6.25 × 10¹⁸ electrons per second, or 1 coulomb per second.

CBSE Class 6 Maths - Playing With Numbers - NCERT Exercise 3.5 (#cbsenotes)

Playing With Numbers

EXERCISE 3.5

CBSE Class 6 Maths

Q1: Which of the following statements are true?
(a) If a number is divisible by 3, it must be divisible by 9.
(b) If a number is divisible by 9, it must be divisible by 3.
(c) A number is divisible by 18, if it is divisible by both 3 and 6.
(d) If a number is divisible by 9 and 10 both, then it must be divisible by 90.
(e) If two numbers are co-primes, at least one of them must be prime.
(f) All numbers which are divisible by 4 must also be divisible by 8.
(g) All numbers which are divisible by 8 must also be divisible by 4.
(h) If a number exactly divides two numbers separately, it must exactly divide their sum.
(i) If a number exactly divides the sum of two numbers, it must exactly divide the two numbers separately.


Answer:
(a) ✗ (e.g. 15 is divisible by 3 but not by 9)
(b) ✔
(c) ✔
(d) ✔
(e) ✗ (e.g. 8 and 9 are co-primes and none of these are prime. )
(f) ✗
(g) ✔
(h) ✔
(i) ✗


Q2: Here are two different factor trees for 60. Write the missing numbers.

CBSE Class 9 - Science - Unit Test Paper (2017-18) (#cbsepapers)

CBSE Class 9 - Science Unit  Test Paper (2017-18)

Chapters Covered In Unit Paper:
   1. Straight Line Motion
   2. Cell - Fundamental Unit Of Life
   3. Matter and Its Surroundings

CBSE Class 11/12, AIPMT/NEET - Biology - List of Important Proteins and Their Occurrence (#cbsenotes)(#biologynotes)

List of Important Proteins and Their Occurrence

Protein	Found Where
Albumin	Egg White, Milk, Blood Plasma
Actin	Muscle Fibres (Contractile protein)
Collagen	Tendon, Bones
Casein	Milk, Egg Yolk
Keratin	Hair, Horn, feathers, Nail
Cytochrome	Mitochondria
Elastin	Arteries, Ligaments,Yellow Fibres

CBSE Class 6 Maths - Playing With Numbers - NCERT Exercise 3.4 (#cbsenotes)

Playing With Numbers

EXERCISE 3.4

CBSE Class 6 Maths

Q1: Find the common factors of :
(a) 20 and 28 
(b) 15 and 25
(c) 35 and 50 
(d) 56 and 120

Answer:
(a) Factors of 20 = 1, 2, 4, 5, 10, 20
Factors of 28 = 1, 2, 4, 7, 14, 28
Common factors = 1, 2, 4

(b) Factors of 15 = 1, 3, 5, 15
Factors of 25 = 1, 5, 25
Common factors = 1, 5

(c) Factors of 35 = 1, 5, 7, 35
Factors of 50 = 1, 2, 5, 10, 25, 50
Common factors = 1, 5

(d) Factors of 56 = 1, 2, 4, 7, 8, 14, 28, 56
Factors of 120 = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 60, 120
Common factors = 1, 2, 4, 8