Model Questions
1. The L.C.M of 24, 36 and 40 is?
1) 120 2) 180 3) 240 4) 360 5) 720
Sol:
Ans: 4
2. The LCM of 
1) 12 2) 24 3) 18 4) 6 5) 3
Sol:
Ans: 2
3. The LCM of 23 × 34 × 57, 24 × 32 × 75, 28 × 33 × 54 × 119 is.....
1) 24 × 33 × 57 × 75
2) 28 × 34 × 57 × 75 × 119
3) 23× 32 × 54 × 119
4) 28 × 33 × 54 × 75 × 119
5) 48 × 33 × 24 × 35 × 119
Sol:
Ans: 2
4. Find the least number which when divided by 18, 24 and 40 leaves remainders 12, 18 and 34 respectively?
1) 354 2) 360 3) 366 4) 372 5) 255
Sol:
Ans: 1
5. Find the least number which when divided by 20, 35, 40 and 60 leaves the remainder in each case is 7?
1) 420 2) 567 3) 847 4) 840 5) 777
Sol:
Ans: 3
6. The smallest number, which when decreased by 5 is divisible by each of 12, 24 and 36 is...
1) 72 2) 149 3) 144 4) 77 5) 66
Sol:
Ans: 4
7. What will be the least number which when doubled will be exactly divisible by 12, 18, 21 and 30?
1) 196 2) 630 3) 1260 4) 2520 5) 930
Sol:
Ans: 2
8. The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is....
1) 74 2) 94 3) 184 4) 364 5) 284
Sol:
Ans: 4
9. Find the least number which is a perfect square and also divisible by 12, 36, 60 and 150 is.....
1) 1800 2) 3600 3) 1600 4) 6400 5) 900
Sol:
Ans: 5
10. 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?
1) 4 2) 15 3) 10 4) 16 5) 30
Sol:
Ans: 4
11. The GCD of 1.08, 0.36 and 0.9 is.....
1) 0.03 2) 0.9 3) 0.18 4) 0.108 5) 1.18
Sol:
Ans: 3
12. Find the HCF of 
Sol:
Ans: 4
13. Find the HCF of 22 × 32 × 72, 2 × 34 × 7
1) 128 2) 126 3) 146 4) 434 5) 224
Sol:
Ans: 2
14. The largest number which divides 75, 144, 178 and 247 to leave the remainder 5, 4, 3 and 2 respectively?
1) 35 2) 70 3) 25 4) 15 5) 36
Sol:
Ans: 1
15. Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case?
1) 4 2) 7 3) 9 4) 13 5) 8
Sol:
Ans: 1
16. The capacity of two pots is 120 liters and 56 liters respectively. The capacity of a container which can exactly measure the contents of the two pots is?
1) 7500 c.c. 2) 7850 c.c. 3) 8000 c.c. 4) 9500 c.c. 5) 8400 c.c.
Sol:
Ans: 3
17. Find the largest number of four digits which is exactly divisible by 27, 18, 12, 15.
1) 9700 2) 9710 3) 9720 4) 9730 5) 10021
Sol:
Ans: 3
18. The ratio of two numbers is 4 : 5 and their HCF is 6. Then their LCM is......
1) 130 2) 120 3) 150 4) 160 5) 60
Sol:
Ans: 2
19. LCM of two numbers is 225 and their HCF is 5. If one number is 25, the other number will be......
1) 5 2) 25 3) 45 4) 225 5) 20
Sol:
Ans: 3
20. The LCM of two numbers is 12 times their HCF. The sum of the HCF and the LCM is 403. If one of the number is 93, then the other number is....
1) 124 2) 128 3) 134 4) 138 5) 96
Sol:
Ans: 1
Practice Questions
1. The HCF and LCM of two numbers are 13 and 455 respectively. If one of the numbers lies between 75 and 125, then that number is....
1) 117 2) 91 3) 100 4) 81 5) 104
2. About the no. of pairs which have 16 as their HCF and 126 as their LCM, we can definitely say that...
1) only one such pair exists
2) no such pair exists
3) many such pairs exists
4) only three such pairs exist
5) only two such pairs exist
3. The sum of two numbers is 629 and their HCF is 37. How many pairs of such numbers can be formed?
1) 3 2) 6 3) 9 4) 8 5) 10
4. The product of two numbers is 2028 and their HCF is 13. The number of such pairs is....
1) 1 2) 2 3) 3 4) 4 5) 8
KEY: 1-2 2-2 3-4 4-2
