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. 18)
18.
The ratio of two numbers is 3 : 4 and their H.C.F. is 4. Their L.C.M. is:
Answer: Option
Explanation:
Let the numbers be 3x and 4x. Then, their H.C.F. = x. So, x = 4.
So, the numbers 12 and 16.
L.C.M. of 12 and 16 = 48.
Discussion:
35 comments Page 3 of 4.
Sukumar Satyen said:
1 decade ago
Let the numbers be 3x and 4x.
We know that 3x*4x = HCF*LCM.
=> 12x^2 = 4*LCM.
=> LCM = 3x^2.....equation (1).
L.C.M. of 3x, 4x = 12x.....equation (2).
Now, equation(1) = equation(2).
=> 3x^2 = 12x.
=> x = 4.
=> L.C.M = 12x = 12*4 = 48.
Thanks.
We know that 3x*4x = HCF*LCM.
=> 12x^2 = 4*LCM.
=> LCM = 3x^2.....equation (1).
L.C.M. of 3x, 4x = 12x.....equation (2).
Now, equation(1) = equation(2).
=> 3x^2 = 12x.
=> x = 4.
=> L.C.M = 12x = 12*4 = 48.
Thanks.
Neha said:
1 decade ago
You can't get 48 by 4/192 you can get 48 by 192/4.
Arjun singh said:
1 decade ago
3x = 3 (4 H.C.F) = 12.
4x = 4 (4 H.C.F) = 16.
LCM of 12 & 16.
12 = 2*2*3.
16 = 2*2*2*2.
Now we have 2*2*3*2*2*2*2 = 192.
HCF = 4/LCM 192.
4/192 = 48 answer.
Got it or not.
4x = 4 (4 H.C.F) = 16.
LCM of 12 & 16.
12 = 2*2*3.
16 = 2*2*2*2.
Now we have 2*2*3*2*2*2*2 = 192.
HCF = 4/LCM 192.
4/192 = 48 answer.
Got it or not.
Mintu bhusan Singha said:
1 decade ago
Excellent information.
Pritam said:
1 decade ago
Initially let the two numbers be 3x and 4x and there given h.c.f is 4.
So that means 3*x and 4*x are the product of a number and a variable which is = to the product of h.c.f and l.c.m as we know.now h.c.f given here is 4.
So put 4 instead of x and get the numbers i.e 12 and 16.
Find the l.c.m of these two numbers i.e 48.
So that means 3*x and 4*x are the product of a number and a variable which is = to the product of h.c.f and l.c.m as we know.now h.c.f given here is 4.
So put 4 instead of x and get the numbers i.e 12 and 16.
Find the l.c.m of these two numbers i.e 48.
Mohanlal Vishwanathan Nair said:
1 decade ago
3:4 = 3*4 = 12.
12*HCF = 12*4 = 48.
12*HCF = 12*4 = 48.
Rosy said:
1 decade ago
As nisha said,
a*b = lcm*hcf
3*4 = 4*lcm
We get value lcm = 3.
Why can't we do in this method?
a*b = lcm*hcf
3*4 = 4*lcm
We get value lcm = 3.
Why can't we do in this method?
Nik said:
1 decade ago
@Kinjal.
Find out the common multiple of 4&3 you will get the answer.
Find out the common multiple of 4&3 you will get the answer.
Kinjal said:
1 decade ago
I understand that assume numbers are 3x & 4x so hcf is x. But now how x is equals to 4?
Karan kashyap said:
1 decade ago
Easy and time saving trick is.
3:4= 3*4 = 12.
12*hcf=>>>> 12*4=48 answer.
3:4= 3*4 = 12.
12*hcf=>>>> 12*4=48 answer.
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