HCF and LCM Important questions

Hello friends this is some important questions of HCF and LCM . I hope it's helpful for you and these questions help you to increase your confidence level .

1. If three numbers are 2a,5a and 7, then what will be their LCM ?

(A) 70a 

(B) 65a

(C) 75a

(D) 70a

(E) None of these 

2. What will be the HCF of ( 2*3*7*9), (2*3*9*11) and (2*3*4*5) ? 

(A) 42

(B) 54

(C) 6

(D) 1386

3. The product of HCF and LCM of 18 and 15 is : 

(A) 120

(B) 150

(C) 175

(D) 270

4. The LCM of two numbers is 2376 while their HCF is 33 . If one of the numbers is 297 , then the another number is : 

(A) 216 

(B) 264

(C) 642

( D) 792 

5. The HCF and LCM of two natural numbers are 12 and 72 , respectively . What is the difference between the two numbers , if one of the number is 24 ? 

(A) 12

(B) 18

(C) 21

(D) 24

5. The ratio of two numbers is 3:4 and their HCF is 4 . What will be their LCM?

(A) 12

(B) 16

(C) 48

(D) 24

6. What is the greatest four - digit number which divided by 10, 15, 21 and 28 leaves remainder 4, 9, 15, and 22, respectively?

(A) 9654

(B) 9666

(C) 9664

(D) 9864

(E) None of these

7. The product of two whole numbers is 1500 and their HCF is 10. Find the LCM .

(A) 15000

(B) 150

(C) 1500

(D) 15

(E) None of these

8. The difference of two numbers is 1/9 of their sum and their sum is 45. Find the LCM. 

(A) 225

(B) 100 

(C) 150

(D) 200

9. Find the HCF of 144, 180 and 192. 

(A) 540 

(B) 432

(C) 36

(D) 12

10. Find the HCF of 1/2, 3/4 and 4/5 ,

(A) 1/20

(B) 1/40

(C) 20

(D) 15