Searching for "L.C.M"

Q:

Find the G.C.F. & L.C.M. of 20 and 28.

 

A) 20,280 B) 5,280
C) 10,140 D) 4,140
 
Answer & Explanation Answer: B) 5,280

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Inventions
Exam Prep: Bank Exams

Q:

Find the L.C.M of 4/5, 2/3 and 5/7.

A) 25 B) 20
C) 40 D) 30
 
Answer & Explanation Answer: B) 20

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM
Exam Prep: Bank Exams

Q:

H.C.F of 3240, 3600 and a third number is 36 and their L.C.M is 24 x 35 x 52 x 72 . What is the third number?

A) 47628 B) 49874
C) 24157 D) 42146
 
Answer & Explanation Answer: A) 47628

Explanation:

hcf_of_three_numbers_3240,_3600_and_third_number_is_361542439249.jpg image

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

Q:

If the sum of two numbers is 55 and the H.C.F. and L.C.M. of these numbers are 5 and 120 respectively, then the sum of the reciprocals of the numbers is equal to ?

A) 13/125 B) 14/57
C) 11/120 D) 16/41
 
Answer & Explanation Answer: C) 11/120

Explanation:

Let the numbers be a and b.
We know that product of two numbers = Product of their HCF and LCM
Then, a + b = 55 and ab = 5 x 120 = 600.
=> The required sum = (1/a) + (1/b) = (a+b)/ab
=55/600 = 11/120

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

Q:

Three numbers are in the ratio of 3:4:5 and their L.C.M is 3600.Their HCF is:

A) 40 B) 60
C) 100 D) 120
 
Answer & Explanation Answer: B) 60

Explanation:

Let the numbers be 3x, 4x, 5x.

 

Then, their L.C.M = 60x.

 

So, 60x=3600 or x=60.

 

Therefore,  The numbers are (3 x 60), (4 x 60), (5 x 60).

 

Hence,required H.C.F=60

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM
Exam Prep: CAT
Job Role: Bank PO

Q:

L.C.M of two prime numbers x and y (x>y) is 161. The value of 3y-x is :

A) -2 B) -1
C) 1 D) 2
 
Answer & Explanation Answer: A) -2

Explanation:

 H. C. F of two prime numbers is 1.  Product of numbers = 1 x 161 = 161.

 Let the numbers be a and b . Then , ab= 161.

 Now, co-primes with  product 161 are (1, 161) and (7, 23).

 Since x and y are prime numbers and x >y , we have x=23 and y=7.

 Therefore,  3y-x = (3 x 7)-23 = -2

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM

Q:

The H.C.F and L.C.M of two numbers are 11 and 385 respectively. If one number lies between 75 and 125 , then that number is

A) 77 B) 88
C) 99 D) 110
 
Answer & Explanation Answer: A) 77

Explanation:

Product of numbers = 11 x 385 = 4235

 

Let the numbers be 11a and 11b . Then , 11a x 11b = 4235  =>  ab = 35

 

Now, co-primes with product  35 are (1,35) and (5,7)

 

So, the numbers are ( 11 x 1, 11 x 35)  and (11 x 5, 11 x 7)

 

Since one number lies 75 and 125, the suitable pair is  (55,77)

 

Hence , required number = 77

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM

Q:

Product of two co-prime numbers is 117. Their L.C.M  should be

A) 1 B) 117
C) Equal to their H.C.F D) cannot be calculated
 
Answer & Explanation Answer: B) 117

Explanation:

H.C.F of co-prime numbers is 1. So, L.C.M = 117/1 =117

Report Error

View Answer Report Error Discuss

Filed Under: HCF and LCM