## NCERT 6TH CLASS MATHEMATICS CHAPTER PLAYING WITH NUMBERS EXERCISE

** OBJECTIVE TYPE**

Q.1 The HCF of two numbers is 11 and their LCM is 7700. If one of the numbers is 275, then the other is

(A) 279 (B) 283 (C) 308 (D) 318

Q.2 Product of two co-prime numbers is 117. Their LCM should be

(A) 1 (B) 117

(C) equal to their HCF (D) cannot be calculated

Q.3 The LCM and HCF of two numbers are 4125 and 25 respectively. One number is 375. Find by how much is the second number less than the first?

(A) 100 (B) 50 (C) 75 (D) 25

Q.4 Three city tour buses leave the bus stop at 9.00 AM. Bus A returns every 30 minutes, but B returns every 20 minutes and Bus C returns every 45 minutes.

What is the next time, the buses will all return at the same time to the bus stop.

(A) 1:00 PM (B) 12 noon (C) 7:00 PM (D) 11:30 PM

Q.5 The least number of 5-digits which is exactly divisible by 16, 24, 36 and 54 is

(A) 10638 (B) 10368 (C) 13068 (D) 1084

Q.6 Find the greatest number of 5-digit which when divided by 3, 5, 8 and 12 will have 2 as reminder

(A) 99999 (B) 99958 (C) 99960 (D) 99962

Q.7 The length and breadth of a room are 18 m and 28 m respectively. What is the greatest length of the side of a square tile required for pairing the floor of the room (No space is to be left in the room without a tile)

(A) 2.4 m (B) 4 m (C) 2 m (D) 3.2 m

Q.8 The prime factorisation of 54 is :

(A) 2 × 2 × 3 × 3 (B) 2 × 2 × 2 × 3 (C) 2 × 3 × 3 × 3 (D) 2 × 27

Q.9 Which of the following is a pair of twin primes?

(A) (7, 9) (B) (17, 19) (C) (51, 53) (D) (31, 33)

Q.10 The only even prime number is :

(A) 2 (B) 3 (C) 4 (D) 0

Q.11 LCM of 15, 20 and 30 is :

(A) 50 (B) 20 (C) 60 (D) 15

Q.12 The smallest digit to make the number 5703_2 divisi

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