Number Play Class 6 MCQ Maths Chapter 3

Regular revision with Class 6 Maths MCQ with Answers and Ganita Prakash Class 6 Maths Chapter 3 Number Play MCQ improves accuracy in objective exams.

MCQ on Number Play Class 6

Number Play MCQ Class 6

Class 6 Maths Number Play MCQ

Question 1.
How many supercells are there in the table below?

4532	1234	3165	3995
6721	8751	4987	1087
5421	3456	6134	5601
2136	4500	2180	3579

(a) 4
(b) 6
(c) 7
(d) 9
Solution:
(a) 4
We know, a cell is a supercell if the number in it is greater than the numbers in its neighbouring cells that are immediately to the left, right, top and bottom.

4532	1234	3165	3995
6721	8751	4987	1087
5421	3456	6134	5601
2136	4500	2180	3579

Thus, cell containing 3995 is a supercell as 3995 is greater than the numbers in its neighbouring cells i.e. 3165 and 1087.

Cell containing 8751 is a supercell as 8751 is greater than the numbers in its neighbouring cells i.e. 1234, 6721, 3456 and 4987.

Cell containing 6134 is a supercell as 6134 is greater than the numbers in its neighbouring cells i.e. 4987, 3456, 2180 and 5601.

Cell containing 4500 is a supercell as 4500 is greater than the numbers in its neighbouring cells i.e. 3456, 2136 and 2180. So, there are 4 supercells.

Question 2.
If there are 7 cells in a row, then the maximum number of supercells possible is:
(a) 3
(b) 4
(c) 5
(d) 6
Solution:
(b) 4
Given, number of cells in a row, n = 7 (Odd number)
So, maximum number of supercells = \(\frac{n+1}{2}\)
= \(\frac{7+1}{2}=\frac{8}{2}\) = 4

Question 3.
Which of the following numbers should be filled in the empty cell such that there are 4 supercells in the table given below?

162	393	297
236		453
193	503	384

(a) 256
(b) 128
(c) 7
(d) 9
Solution:
(b) 128
In a grid, a cell is a supercell if the number in it is greater than the numbers in the neighbouring cells that are immediately to the left, right, top and bottom.
If 256 is filled in the empty cell, then there would be 3 supercells only.

162	393	297
236	256	453
193	503	384

If 128 is filled in the empty cell, then there would be 4 supercells.

162	393	297
236	128	453
193	503	384

If 421 is filled in the empty cell, then there would be 2 supercells only.

162	393	297
236	421	453
193	503	384

If 625 is filled in the empty cell, then there would be 1 supercell only.

162	393	297
236	625	453
193	503	384

Question 4.
Identify the numbers marked on the number line below.

What is the value of (x + y)?
(a) 10475
(b) 10480
(c) 10485
(d) 10490
Solution:
(d) 10490
There are 3 sub-divisions between 5240 and 5255.
Therefore, each sub-division represents
\(\frac{5255-5240}{3}=\frac{15}{3}\) = 5 numbers.
Thus, the labelled number line is shown below.

So, x = 5230 and y = 5260
Now, x + y = 5230 + 5260 = 10490

Question 5.
What is the highest sum of digits of a number between 35 and 45?
(a) 12
(b) 11
(c) 13
(d) 9
Solution:
(a) 12
Numbers between 35 and 45 are: 36, 37, 38, 39, 40, 41, 42, 43 and 44.

Numbers	Sum of digits
36	3 + 6 = 9
37	3 + 7 = 10
38	3 + 8 =11
39	3 + 9 = 12 (Highest)
40	4 + 0 = 4
41	4 + 1 = 5
42	4 + 2 = 6
43	4 + 3 = 7
44	4 + 4 = 8

Question 6.
In the number line pattern, if you are moving from 105 to 125 and then from 125 to 145, what will be the number after moving from 145 with the same pattern?
(a) 160
(b) 165
(c) 170
(d) 175
Solution:
(b) 165
First movement: From 105 to 125
Second movement: From 125 to 145
Next movement: From 145 to 145 + 20 = 165
So, the required number is 165.

Question 7.
Among the numbers 1 – 100, how many times will the digit ‘5’ occur?
(a) 19
(b) 20
(c) 21
(d) 22
Solution:
(b) 20
Numbers that contain digit ‘5’ are:
5, 15, 25, 35, 45, 50, 51, 52, 53, 54, 55(it has two 5s), 56, 57, 58, 59, 65, 75, 85 and 95
Thus, digit ‘5’ occurs 20 times.

Question 8.
Which of the following is a palindromic number?
(a) 1212
(b) 1331
(c) 4141
(d) 1009
Solution:
(b) 1331
We know, palindromic numbers read the same from left to right and right to left.
Thus, 1331 is a palindromic number.

Question 9.
What is the smallest sum of digits of a number from 116 to 125?
(a) 2
(b) 3
(c) 6
(d) 7
Solution:
(b) 3
Numbers from 116 to 125 are: 116, 117, 118, 119, 120, 121, 122, 123, 124 and 125.

Numbers	Sum of digits
116	1 + 1 + 6 = 8
117	1 + 1 + 7 = 9
118	1 + 1 + 8 = 10
119	1 + 1+ 9 =11
120	1 + 2 + 0 = 3 (smallest)
121	1 + 2 + 1 = 4
122	1 + 2 + 2 = 5
123	1 + 2 + 3 = 6
124	1 + 2 + 4 = 7
125	1 + 2 + 5 = 8

Question 10.
What is the sum of the smallest and largest 2-digit numbers with unique digits?
(a) 108
(b) 110
(c) 100
(d) 121
Solution:
(a) 108
Smallest 2-digit number with unique digits = 10
Largest 2-digit number with unique digits = 98
Required sum = 10 + 98 = 108

Question 11.
If you subtract the smallest 2-digit even number from smallest 3-digit odd number, what is the result?
(a) 91
(b) 81
(c) 101
(d) 110
Solution:
(a) 91
Smallest 2-digit even number = 10
Smallest 3-digit odd number = 101
Now, 101 – 10 = 91

Question 12.
A 24-hour digital clock is showing 14:41 now. How many minutes until the clock shows the next palindromic time?
(a) 60 minutes
(b) 70 minutes
(c) 80 minutes
(d) 90 minutes
Solution:
(b) 70 minutes
Time now = 14:41 and next palindrome time = 15:51
Thus, 15:51 – 14:41 = 1 hr 10 mins
=70 minutes
Hence, the clock shows the next palindromic time after 70 minutes.

Question 13.
The 5^th term in the Collatz sequence starting with 21 is:
(a) 8
(b) 16
(c) 10
(d) 17
Solution:
(a) 8
The rule followed by a Collatz sequence is: Start with any number; if the number is even, take half of it; if the number is odd, multiply it by 3 and add 1; repeat till 1 is obtained.
First term: 21
Second term: 3 × 21 + 1 = 64
[As 21 is an odd number.]
Third term: \(\frac{64}{2}\) = 32 [As 64 is an even number.]
Fourth term: \(\frac{32}{2}\) = 16
[As 32 is an even number.]
Fifth term: \(\frac{16}{2}\) = 8 [As 16 is an even number.]
Hence, the required term is 8.

Question 14.
The sum of 3^rd and 5^th terms in the Collatz sequence starting with 100 is:
(a) 28
(b) 63
(c) 34
(d) 41
Solution:
(b) 63
First term: 100
Second term: \(\frac{100}{2}\) = 50
[As 100 is an even number.]
Third term: \(\frac{50}{2}\) = 25
[As 50 is an even number.]
Fourth term: 3 × 25 + 1 = 76
[As 25 is an odd number.]
Fifth term: y = \(\frac{76}{2}\) [As 76 is an even number.]
Hence, the sum of 3^rd and 5^th terms = 25 + 38
= 63

Question 15.
Which of the following numbers are numbers in the collatz sequence starting with 18?
(i) 19
(ii) 52
(iii) 17
(iv) 35
Choose the correct option from the following:
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Solution:
(b) (ii) and (iii)
Rule: If the number is even, divide by 2.
If the number is odd, multiply by 3 and add 1.
18 → 9 → 28 → 14 → 7 → 22 → 11 → 34 → 17 → 52 → 26 → 13 → 40 → 20 → 10 → 5 → 16 → 8 → 4 → 2 → 1
From the given numbers, 17 and 52 are present in the Collatz sequence starting with 18.

Question 16.
Which of the following numbers are Supercells in the given grid?

109	62	573	432
101	673	809	84
572	961	274	340
209	173	114	200
381	524	468	93

(i) 673
(ii) 468
(iii) 809
(iv) 109
Choose the correct option from the following:
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Solution:
(c) (iii) and (iv)
809 and 961 are greater than 673 in its neighbourh ood.
So, 673 is not a supercell.
524 is greater than 468 in its neighbourhood. So, 468 is not a supercell

There is no number greater than 809 in its neighbourhood, i.e. 573, 673, 84 and 274.
So, 809 is a supercell.
There is no number greater than 109 in its neighbourhood, i.e. 62 and 101.
So, 109 is a supercell.

Question 17.
Which of the following numbers are palindrome and have digit sum equal to 14?
(i) 545
(ii) 2552
(iii) 3434
(iv) 1771
Choose the correct option from the following:
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Solution:
(a) (i) and (ii)
545, 2552 and 1771 are palindromes but digit sum of 1771 is not 14.
1 + 7 + 7 + 1 = 16
3434 is not a palindrome as we get 4343 on reversing the digits, which is not same as 3434.

Number Play Class 6 Assertion and Reason Questions

The following questions are Assertion and Reason based questions. Two statements are given, one labelled as Assertion (A) and the other is labelled as Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Question 1.
(A): The coloured cell is die supercell in the given table.

15000

15500

16000

16500

(R): In a row, a cell is a supercell if the number in it is greater than the numbers in the neighbouring cells that are immediately to the left and right.
Solution:
(d) A is false but R is true.
We know, a cell is a supercell if the number in it is greater than the numbers in its neighbouring cells that are immediately to the left and right. Here, 16000 is greater than 15500 but smaller than 16500.
Thus, Assertion (A) is lalse, but Reason (R) is true.

Question 2.
(A): If 120 is the largest number in a grid, then cell containing 120 is a supercell.
(R): The cell having the largest number in a grid is always a supercell.
Solution:
(a) Both A and R are true and R is the correct explanation of A.
If a number is the largest number in a grid, then it will be greater than all the numbers in its neighbouring cells.
Thus, the cell having the largest number in a grid is always a supercell.
Thus, both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).

Question 3.
(A): The cell containing 4500 is a supercell in the given table.

5100	4900	4600
4700	4500	5000
3900	4800	5300

(R): 4500 is smaller than 4900, 4700, 4800 and 5000.
Solution:
(d) A is false but R is true.
We know, a cell is a supercell if the number in it is greater than the numbers in the neighbouring cells that are immediately to the left, right, top and bottom.

As 4500 is smaller than 4900, 4700, 4800 and 5000, the cell containing 4500 is not a supercell. Thus, Assertion (A) is false, but Reason (R) is true.

Number Play Class 6 Fill in the Blanks

Question 1.
Two adjacent cells _______ be supercells.
Solution: cannot
Two adjacent cells cannot be supercells.

Question 2.
The cell having the ____ number in a grid is always a supercell.
Solution: largest
The cell having the largest number in a grid is always a supercell.

Question 3.
On the number line, a smaller number is always to the ______of a larger number.
Solution: left
On the number line, a smaller number is always to the left of a larger number.

Question 4.
The digits of number 7203 adds up to _______ .
Solution: 12
Sum of digits of 7203 is 7 + 2 + 0 + 3 = 12.

Question 5.
The total number of 4-digit numbers is __________ .
Solution: 9000
Smallest 4-digit number = 1000
Largest 4-digit number = 9999
The total number of 4-digit numbers = 9999 – 1000 + 1 = 9000

Question 6.
The largest palindromic number between 700 and 800 is _______ .
Solution: 797
The largest palindromic number between 700 and 800 is 797.

Question 7.
The next number in the Collatz sequence after 24 is __________ .
Solution: 12
Since 24 is an even number, the next number is \(\frac{24}{2}\) = 12.