Number Play Class 7 MCQ
hardNumber Play Class 7 MCQ
Number Play Class 7 MCQ
Question 1.
The nth odd number is given by
(a) 3n - 1
(b) 3n + 1
(c) 2n + 1
(d) 2n - 1
Solution:
(d) 2n - 1
Question 2.
The nth even number is given by
(a) 2n - 2
(b) 2n
(c) 2n + 2
(d) 4n
Solution:
(b) 2n
Question 3.
In the given magic square, the sum of the numbers of each diagonal will be
(a) 70
(b) 105
(c) 115
(d) 135
Solution:
(b) 105
Question 4.
The next number in the Virahanka- Fibonacci sequence 1, 2, 3, 5, 8, 13, 21, 34, ... is
(a) 55
(b) 53
(c) 54
(d) 52
Solution:
(a) 55
Question 5.
The number of all rhythms of short and long syllables with 10 beats is
(a) 144
(b) 89
(c) 55
(d) 34
Solution:
(b) 89
Case Study
Question 1.
A student of class VII was constructing a 3 × 3 magic square and filled some numbers as shown on the blackboard, out of 9 consecutive numbers.
(a) Will he be able to construct the magic square? Why or why not?
(b) If not, construct the correct magic square.
(c) What should be the magic sum of the square?
(d) Write all the 9 consecutive numbers used by you.
(e) What is total sum of these numbers?
Solution:
(a) No. Because the number 13 has been written at a corner place.
(b) One correct magic square is as given below :
(c) Its magic sum is 9 × 3 = 27.
(d) The nine consecutive numbers are 5, 6, 7, 8, 9, 10, 11, 12 and 13.
(e) Total sum = 27 × 3 = 81.
Question 2.
The teacher wrote the following Cryptarithm problem on the blackboard :
(a) What is the value of A?
(b) What is the value of B?
(c) What is the difference between B and A?
(d) What is the parity of A?
(e) What is the parity of B?
(f) What is the parity of A × B?
Solution:
(a) By observing the problem, A = 8.
(b) B = 9.
(c) Difference = 9 - 8 = 1.
(d) Parity of A is even.
(e) Parity of B is odd.
(f) Parity of A × B = 8 × 9, i.e., 72 is even.