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
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 1 of 4.

Jayshree said:   1 decade ago
Let the numbers be 3x and 4x. Then, their H.C.F. = x. So, x = 4.
i understand this step but i dont understand this step he numbers 12 and 16. please explain.

Suyash said:   1 decade ago
Hey jayshree

Given hcf = 4
=3x=3x4=12
4x=4x4=16
multiply 3 with 16 and 4 with 12 answer is 48

got it!

Nisha said:   1 decade ago
Please tell me why use h.c.f value instead of x

hcf * lcm= pro. of no
4*lcm=3x*4x
lcm=3x*4x/4

reply according to this

Reuben said:   1 decade ago
hcf of any two numbers is a factor of those two numbers .. means example if u take hcf of 12 and 18 .. its 6 .. it means 6 is a factor of 12 and 18. 6*2=12 6*3=18
now if i say there are two numbers in ratio 2:3 whose hcf is 6 how will u write the two numbers ??
solve my question and u will understand it
ans: hcf*2 is one number hcf*3 is the other
(1)

Fakir chand bhatt said:   1 decade ago
L.C.M. OF 3 : 4 IS ............. 12
AND THE H.C.F IS GIVEN 4 IN THE QUESTION

NOW , REQUIRED NUMBER IS [12*4] = 48 ANSWER

IS THE WAY IS RIGHT OR NOT.........

Karan kashyap said:   1 decade ago
Easy and time saving trick is.

3:4= 3*4 = 12.

12*hcf=>>>> 12*4=48 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?

Nik said:   1 decade ago
@Kinjal.

Find out the common multiple of 4&3 you will get the answer.

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?

Mohanlal Vishwanathan Nair said:   1 decade ago
3:4 = 3*4 = 12.

12*HCF = 12*4 = 48.


Post your comments here:

Your comments will be displayed after verification.