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. 17)
17.
What will be the least number which when doubled will be exactly divisible by 12, 18, 21 and 30 ?
Answer: Option
Explanation:
L.C.M. of 12, 18, 21 30 2 | 12 - 18 - 21 - 30
----------------------------= 2 x 3 x 2 x 3 x 7 x 5 = 1260. 3 | 6 - 9 - 21 - 15
----------------------------Required number = (1260 ÷ 2) | 2 - 3 - 7 - 5
= 630.Discussion:
30 comments Page 1 of 3.
Krishna said:
2 weeks ago
But 630 is not exactly divisible by 12 it's 52. 5.
@Vradhi.
They asked that the doubled number needs to be divisible by the given number, which means 630 doubled is 1260.
So, it's divisible, then 630 is the answer.
@Vradhi.
They asked that the doubled number needs to be divisible by the given number, which means 630 doubled is 1260.
So, it's divisible, then 630 is the answer.
Madhur Nanhorya said:
10 months ago
Guys just divide each option by 30, so you will see
196/30 ==> r!=0
630/30 ==> r =0,
1260/30 ==> r=0,
2520/30 ==> r = 0, so the least number divisible by 30 is 630 so it must be divisible by other numbers.
As well according to the question,
So option b) 630 no need to find the LCM here.
196/30 ==> r!=0
630/30 ==> r =0,
1260/30 ==> r=0,
2520/30 ==> r = 0, so the least number divisible by 30 is 630 so it must be divisible by other numbers.
As well according to the question,
So option b) 630 no need to find the LCM here.
(3)
ASHLY said:
2 years ago
Very simple,
Let the last number be 'x' ;
And given the least number is doubled then it will become '2x'.
Now,
L.C.M of (12,18,21,30) is 1260,
2x = 1260.
x = 630.
THANKS!
Let the last number be 'x' ;
And given the least number is doubled then it will become '2x'.
Now,
L.C.M of (12,18,21,30) is 1260,
2x = 1260.
x = 630.
THANKS!
(70)
Abhi said:
2 years ago
21x30 = 630.
So, the Answer is 630.
So, the Answer is 630.
(2)
Supu said:
4 years ago
Yes right @Vradhi.
Please someone explain it.
Please someone explain it.
Vradhi said:
4 years ago
But 630 is not exactly divisible by 12 it's 52.5.
(12)
Aman said:
4 years ago
Let the least number say x;
And given least number is doubled then it will become =2x;
then,
find lcm (12,18,21,30) we get 1260;
2x = 1260,
x = 630.
And given least number is doubled then it will become =2x;
then,
find lcm (12,18,21,30) we get 1260;
2x = 1260,
x = 630.
(43)
Arun said:
5 years ago
The question itself says that the least number is exactly divisible by (12,18,21,30 ).
The L.C.M of (12,18,21,30) = ( 2*3*2*3*7*5 ) = 1260.
So the least number is 2. 1260÷2.
The L.C.M of (12,18,21,30) = ( 2*3*2*3*7*5 ) = 1260.
So the least number is 2. 1260÷2.
(5)
Yemysle said:
6 years ago
Since the L.C.M is 1260, the question says find the number which when doubled will give exactly as the given number(12,18,21,30) therefore 630 will be doubled to give d LCM(1260) or half if 1260.
(5)
Sanjana said:
6 years ago
Let the number Be N.
Then LCM of 12,18,21,30 is 1260and given that 2N/1260 leaves no remainder.
Now, N/630 this means we have to find the least value of N from options which when divided by 630 leaves no remainder.
Although, options b, c, d leaves no remainder when divided by 630 we had been asked the least value of N, so option 2 i.e., 630 is the answer
Then LCM of 12,18,21,30 is 1260and given that 2N/1260 leaves no remainder.
Now, N/630 this means we have to find the least value of N from options which when divided by 630 leaves no remainder.
Although, options b, c, d leaves no remainder when divided by 630 we had been asked the least value of N, so option 2 i.e., 630 is the answer
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers