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:
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Filed Under: Inventions
Exam Prep: Bank Exams

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

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Filed Under: HCF and LCM
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: 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) 55/601 B) 601/55
C) 11/120 D) 120/11
 
Answer & Explanation Answer: C) 11/120

Explanation:

Let the numbers be a and b.

 

Then, a + b = 55 and ab = 5 x 120 = 600.

 

The required sum =1a+1b = a+bab55600=11120

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Filed Under: HCF and LCM

Q:

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
 
Answer & Explanation Answer: A) 40

Explanation:

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

 

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

 

So, 60x = 2400 or x = 40.

 

 The numbers are (3 x 40), (4 x 40) and (5 x 40).

 

Hence, required H.C.F. = 40.

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Filed Under: HCF and LCM

Q:

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
 
Answer & Explanation Answer: C) 322

Explanation:

Clearly, the numbers are (23 x 13) and (23 x 14).

 

 

 

 Larger number = (23 x 14) = 322.

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