ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions

ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions

Mental Maths
Question 1.
Fill in the blanks:
(i) The only natural number which has exactly one factor is ……….
(ii) The only prime number which is even is ……….
(iii) The HCF of two co-prime numbers is ……….
(iv) Two perfect numbers are ………. and ……….
(v) The only prime-triplet is ……….
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 1

Question 2.
State whether the following statements are true (T) or false (F):
(i) Every natural number has a finite number of factors.
(ii) Every natural number has an infinite number of its multiples.
(iii) There are infinitely many prime numbers.
(iv) If two numbers are separately divisible by a number, then their difference is also divisible by that number.
(v) LCM of two prime numbers equals their product.
(vi) LCM of two co-prime numbers equals their product.
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 2

Question 3.
State whether the following statements are true or false. If a statement is false, justify your answer.
(i) The sum of two prime numbers is always an even number.
(ii) The sum of two prime numbers is always a prime number.
(iii) The sum of two prime numbers can never be a prime number
(iv) No odd number can be written as the sum of two prime numbers.
(v) If two numbers are co-prime, then atleast one of them must be prime.
(vi) If a number is divisible by 18, it must be divisible by 3 and 6 both.
(vii) If a number is divisible by 2 and 4 both, it must be divisible by 8.
(viii) If a number is divisible by 3 and 6 both, it must be divisible by 18.
(ix) HCF of an even number and an odd number is always 1.
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 3
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 4
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 5
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 6

Multiple Choice Questions
Choose the correct answer from the given four options (4 to 28):
Question 4.
All factors of 6 are
(a) 1, 6
(b) 2, 3
(c) 1, 2, 3
(d) 1, 2, 3, 6
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 7

Question 5.
Which of the following is an odd composite number?
(a) 7
(b) 9
(c) 11
(d) 12
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 8

Question 6.
The number of even numbers between 68 and 90 is
(a) 10
(b) 11
(c) 12
(d) 31
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 9

Question 7.
Which of the following is a prime number?
(a) 69
(b) 87
(c) 91
(d) 97
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 10

Question 8.
Which of the following is a pair of twin- prime number?
(a) 19, 21
(b) 43, 47
(c) 59, 61
(d) 73, 79
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 11

Question 9.
The number of distinct prime factors of the largest 4-digit number is
(a) 2
(b) 3
(c) 5
(d) none of these
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 12

Question 10.
The number of distinct prime factors of the smallest 5-digit number is
(a) 2
(b) 4
(c) 6
(d) 8
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 13

Question 11.
The sum of the prime factors of 1729 is
(a) 13
(b) 19
(c) 32
(d) 39
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 14

Question 12.
Which of the following is a pair of co-prime numbers?
(a) 8, 45
(b) 3, 18
(c) 5, 35
(d) 6, 39
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 15

Question 13.
Every natural number has an infinite number of
(a) prime factors
(b) factors
(c) multiples
(d) none of these
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 16

Question 14.
Which of the following numbers is divisible by 4?
(a) 308594
(b) 506784
(c) 732106
(d) 9301538
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 17

Question 15.
Which of the following numbers is divisible by 8?
(a) 503786
(b) 505268
(c) 305678
(d) 703568
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 18

Question 16.
Which of the following numbers is divisible by 3?
(a) 50762
(b) 42063
(c) 52871
(d) 37036
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 19

Question 17.
Which of the following numbers is divisible by 9?
(a) 972063
(b) 730542
(c) 785423
(d) 5612844
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 20

Question 18.
Which of the following numbers is divisible by 6?
(a) 560324
(b) 650374
(c) 798653
(d) 750972
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 21

Question 19.
The digit by which ‘*’ should be replaced in 54 * 281 so that the number formed is divisible by 9 is
(a) 6
(b) 7
(c) 8
(d) 9
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 22

Question 20.
The digit by which should be replaced in 7254 * 98 so that the number formed is divisible by 22 is
(a) 0
(b) 1
(c) 2
(d) 6
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 23

Question 21.
If a number is divisible by 5 and 6 both, then it may not be divisible by
(a) 10
(b) 15
(c) 30
(d) 60
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 24

Question 22.
The number of common prime factors of 60, 75 and 105 is
(a) 2
(b) 3
(c) 4
(d) 5
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 25

Question 23.
The H.C.F. of 144 and 198 is
(a) 6
(b) 9
(c) 12
(d) 18
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 26

Question 24.
The L.C.M. of 30 and 45 is
(a) 15
(b) 30
(c) 45
(d) 90
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 27

Question 25.
The L.C.M. of 4 and 44 is
(a) 4
(b) 11
(c) 44
(d) 176
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 28

Question 26.
The LCM of 7 and 13 is 1
(a) 1
(b) 7
(c) 13
(d) 91
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 29

Question 27.
If H.C.F. of two numbers is 15 and their product is 1575, then their L.C.M. is
(a) 15
(b) 105
(c) 525
(d) 1575
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 30

Question 28.
If the LCM of two natural numbers is 180, then which of the following is not the HCF of the numbers?
(a) 45
(b) 60
(c) 75
(d) 90
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 31
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 32

Value Based Questions
Question 1.
To teach the value of gratitude and appreciation to the students, a school organised a ‘Card Making’ activity in which the students were asked to make “THANK YOU CARDS” for the people who helped them in some way. Assorted cards were made with different titles. Their numbers are given below:
T cards for teachers = 120
F cards for friends = 540
S cards for servants = 90
P cards for parents = 240 and
G cards for grandparents = 150
(i) Find the HCF and LCM of all the different number of cards.
(ii) Find HCF and LCM of maximum and minimum number of cards.
(iii) Is the number of T-cards is a factor of number of P-cards?
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 33
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 34
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 35
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 36

Higher Order Thinking Skills (Hots)
Question 1.
Write 2-digit odd numbers whose sum of digits is 8.
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 37

Question 2.
Write all pairs of 2-digit twin primes such that on changing the places of their digits, they still remain prime numbers.
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 38

Question 3.
There are just four natural numbers less than 100, which have exactly three factors. One of them is 25, what are the other three? What can be said about these numbers?
Solution:
ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 4 Playing with Numbers Objective Type Questions 39

ML Aggarwal Class 6 Solutions for ICSE Maths