HCF and LCM – Railway Maths Part Ⅵ

Total Questions: 50

11. The LCM of 6, 9 and x is 72. Which of the given options can be a possible value of x? [RRB NTPC 17/02/2021 (Evening)]

Correct Answer: (a) 24 

12. What is the HCF of n and n + 1 where n is a natural number? [RRB NTPC 22/02/2021 (Morning)]

Correct Answer: (d) 1

13. The sum of two numbers is 98 and their HCF is 14. How many such pairs can be formed? [RRB NTPC 22/02/2021 (Evening)]

Correct Answer: (c) 3

14. Which of the following statements is true? [RRB NTPC 22/02/2021 (Evening)]

Correct Answer: (c) HCF of fractions = HCF of numerators / LCM of denominators

15. The HCF of two numbers is 30 and LCM is 2310. If one of the numbers is 210, other number is: [RRB NTPC 27/02/2021 (Morning)]

Correct Answer: (b) 330

16. The LCM of 4, 6 and x can not be [RRB NTPC 27/02/2021 (Morning)]

Correct Answer: (c) 18

17. Six bells commence tolling together and toll at the intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In the first 10 minutes, how many times would they have tolled together? [RRB NTPC 27/02/2021 (Evening)]

Correct Answer: (d) 6 times

18. Find the least positive number; which when divided by 5, 6, 8, 9 and 12, gives 1 as a remainder in each case and is completely divisible by 13. [RRB NTPC 01/03/2021 (Morning)]

Correct Answer: (a) 3601

19. Which largest number will divide 627 and 233 leaving remainders of 11 and 13 respectively? [RRB NTPC 01/03/2021 (Evening)]

Correct Answer: (c) 44

20. Two positive numbers are in the ratio 7 : 9 and the product of their LCM and HCF is 25200. The sum of the numbers is: [RRB NTPC 02/03/2021 (Morning)]

Correct Answer: (a) 320