# 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:
12
16
24
48
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:
34 comments Page 1 of 4.

Anki said:   5 months ago
Here, 3 * 4 * 4 = 48.
(2)

Mayur said:   9 months ago
Let,
LCM = LCM of ratio units x(multiply) HCF.
LCM = 12 x 4(given),
LCM = 48.
(3)

Nikita said:   12 months ago
As x = 4.
And no's are given 3x and 4x.
Putting value of x in above equations
3(4) = 12,
4(4) = 16.

Kelbin said:   1 year ago
3/4=4/LCM.
LCM/3=4 * 4,
LCM=16 * 3,
LCM=48.

Manish kumar said:   2 years ago
Let numbers be 3x and 4x.

LCM 12x.

Also 3x *4x=LCM*HCF.
3x*4x=12x.
X=4.
Numbers are 12, 16.

LCM =12x = 48 is the answer.

Tulasi said:   3 years ago
How come x as 4? Please explain to me.

Hema said:   4 years ago
4x*3x = 12x.
12x= 4(hcf),
So x=3.
How 4?

Rahul said:   4 years ago
3x ,4x be the two numbers and the given Question HCF is given so take HCF of (3, 4) = 1x.
So x = 4.
3*4=12,
4*4=16,
LCM = 48.

Arul said:   5 years ago
How x=3 why not 4?

LCM*HCF=product.
X*4=3x*4x.
X=3.

Rupesh said:   5 years ago
Hcf = product/lcm.
= 3*4+4*4/4.
= 48.