LCM & HCF
1.Which of the following is a pair of co-primes ?
a)(16 , 62) b)(18 , 25) c)(21 , 35) d)(23 , 92)
2. The L.C.M. of 23 * 32 * 5 * 11, 24 * 34 * 52 * 7 and 25 * 33 * 53 * 72 * 11 is
a)23 * 32 * 5 b)25 * 34 * 53 c)23 * 32 * 5 * 7 * 11 d)25 * 34 * 53 * 72 * 11
3. The H.C.F of 1.75, 5.6 and 7 is:
a)0.07 b)0.7 c)3.5 d)0.35
4. The G.C.D of 1.08, 0.36 and 0.9 is :
a)0.03 b)0.9 c)0.18 d)0.108
5.The H.C.F. of 0.54, 1.8 and 7.2 is :
a)1.8 b)0.18 c)0.018 d)18
6.The L.C.M. of 3, 2.7 and 0.09 is
a)2.7 b)0.27 c)0.027 d)27
7.Three numbers are in the ratio 1:2:3 and their H.C.F is 12. The numbers are :
a)4, 8, 12 b)5, 10, 15 c)10, 20, 30 d)12, 24, 36
8. Sudhir goes to the market once every 64 days and Sushil goes to the same market once every 72 days. They met each other one day. How many days later will they meet each other again?
a)16 b) 64 c) 240 d) 576
9. The H.C.F of two numbers is 12 and their difference is 12. The numbers are :
a)66, 78 b)70, 82 c)94, 106 d)84, 96
10.The L.C.M. of two numbers is 48. The numbers are in the ratio 2:3. The sum of the numbers is :
a)28 b)32 c)40 d)64
11.The L.C.M. of three different numbers is 120. Which of the following cannot be their H.C.F. ?
a)8 b)12 c)24 d)35
12. The H.C.F. of two numbers is 8. Which one of the following can never be their L.C.M. ?
a)24 b)48 c)56 d)60
13.The H.C.F. of two numbers is 23 and the other two factors of their L.C.M. are 13 and 14. The larger of the two numbers is :
a)276 b)299 c)322 d)345
14.About the number of pairs which have 16 as their H.C.F. and 136 as their L.C.M., We can definitely say that :
a)no such pair exists b)only one such pair exists c)only two such pair exist d)many such pair exist
15. H.C.F of two numbers is 11 and their LCM is 693. If one of the numbers is 77, find the other
a)99 b)66 c)96 d)36
16. Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case.
a)4 b)7 c)9 d)13
17. The H.C.F. of two numbers is 23 and the other two factors of their L.C.M. are 13 and 14. The larger of the two numbers is:
a)276 b)299 c)322 d)345
18. Six bells commence tolling together and toll at intervals of 2, 4, 6, 8 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together ?
a)4 b)10 c)15 d)16
19. Let N be the greatest number that will divide 1305, 4665 and 6905, leaving the same remainder in each case. Then sum of the digits in N is:
a)4 b)5 c)6 d)8
20. The greatest number of four digits which is divisible by 15, 25, 40 and 75 is:
a)9000 b)9400 c)9600 d)9800
21. The product of two numbers is 4107. If the H.C.F. of these numbers is 37, then the greater number is:
a)101 b)107 c)111 d)185
22. Three number are in the ratio of 3 : 4 : 5 and their L.C.M. is 2400. Their H.C.F. is:
a)40 b)80 c)120 d)200
23. The G.C.D. of 1.08, 0.36 and 0.9 is:
a)0.03 b)0.9 c)0.18 d)0.108
24. The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is:
a)1 b)2 c)3 d)4
25. The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is:
a)74 b)94 c)184 d)364
26. Find the lowest common multiple of 24, 36 and 40.
a)120 b)240 c)360 d)480
27. The least number which should be added to 2497 so that the sum is exactly divisible by 5, 6, 4 and 3 is:
a)3 b)13 c)23 d)33
28. The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one of the numbers is 275, then the other is:
a)279 b)283 c)308 d)318
29. The greatest possible length which can be used to measure exactly the lengths 7 m, 3 m 85 cm, 12 m 95 cm is:
a)15 cm b)25 cm c)35 cm d)42 cm
30. The L.C.M. of two numbers is 48. The numbers are in the ratio 2 : 3. Then sum of the number is:
a)28 b)32 c)40 d)64