Aptitude - Problems on H.C.F and L.C.M - Discussion
Discussion Forum : Problems on H.C.F and L.C.M - General Questions (Q.No. 7)
7.
Three number are in the ratio of 3 : 4 : 5 and their L.C.M. is 2400. Their H.C.F. is:
Answer: Option
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.
Discussion:
43 comments Page 4 of 5.
Karan said:
1 decade ago
Better way to find hcf for three numbers is either you could take the differences between them respectively.
Sanjay said:
1 decade ago
Can this approach be applied for any higher co-prime numbers ?
P.vinothini said:
1 decade ago
Please if you don't mine reply what is mean by co-prime?
Master said:
10 years ago
LCM = 2400.
2400/60 = 40 => Right answer.
2400/60 = 40 => Right answer.
Aman Kaushik said:
1 decade ago
Ratio 3:4:5
LCM 2400.
HCF ?
Solve answer = 3*4*5 = 60.
LCM is = 2400.
HCF IS = 2400/60.
= 40.
LCM 2400.
HCF ?
Solve answer = 3*4*5 = 60.
LCM is = 2400.
HCF IS = 2400/60.
= 40.
Sunil sharma said:
1 decade ago
3*40 = 120.
4*40 = 160.
5*40 = 200.
So number is 120, 160, 200.
We are calculate LCM above three number = 2400.
Do answer is 40.
4*40 = 160.
5*40 = 200.
So number is 120, 160, 200.
We are calculate LCM above three number = 2400.
Do answer is 40.
Varun said:
1 decade ago
Its wrong. LCM * HCF = product of numbers is only valid for 2 numbers.
Consider an example for no 2, 15, 20;
LCM = 2*2*3*5 = 60.
While HCF of these two numbers is 1.
Now as per your logic LCM*HCF = product of 2 numbers.
Hence as per this:
60*1 = 2*15*20.
60 != 600.
Hence your logic is invalid please help regarding that.
Consider an example for no 2, 15, 20;
LCM = 2*2*3*5 = 60.
While HCF of these two numbers is 1.
Now as per your logic LCM*HCF = product of 2 numbers.
Hence as per this:
60*1 = 2*15*20.
60 != 600.
Hence your logic is invalid please help regarding that.
Paridhi said:
1 decade ago
Why is LCM 3x X 4x X 5x is the LCM equal to the product of the numbers?
Jayakrishna vinod said:
1 decade ago
What is the use of LCM & HCF in our day to day life?
Karthick said:
1 decade ago
First we have to find original nos.
L.C.M = 2400.
Ratio = 3:4:5.
2400/3 = 800.
2400/4 = 600.
2400/5 = 480.
L.C.M of 800, 600, 480 = 40.
L.C.M = 2400.
Ratio = 3:4:5.
2400/3 = 800.
2400/4 = 600.
2400/5 = 480.
L.C.M of 800, 600, 480 = 40.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers