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. 14)
14.
The least number which when divided by 5, 6 , 7 and 8 leaves a remainder 3, but when divided by 9 leaves no remainder, is:
1677
1683
2523
3363
Answer: Option
Explanation:

L.C.M. of 5, 6, 7, 8 = 840.

Required number is of the form 840k + 3

Least value of k for which (840k + 3) is divisible by 9 is k = 2.

Required number = (840 x 2 + 3) = 1683.

Discussion:
86 comments Page 2 of 9.

Saurabh agrawal said:   1 decade ago
Suchita's trick is great. Very short and productive.

Shariq said:   1 decade ago
Just divide all options by 9.

Simanta said:   1 decade ago
Nice suchita !

M.V.KRISHNA/PALVONCHA said:   1 decade ago
Excellent suchita.

Gogol said:   1 decade ago
@SUCHITA

If one of the option becomes for example..2538, then the sum of 2+5+3+8= 18 will also be divided by 9 leaving no remainder.

So, in this case there is no profit from your logic.

Anand said:   1 decade ago
The solution of finding the option which is divisible by 9 works only in this specific case of provided options. In case, when more than 1 option is divisible by 9, the method to find out the value of k needs to be understood.

Pankaj said:   1 decade ago
Nice Suchita.

Feroz said:   1 decade ago
we get LCM =840 since 843 is divided by 3
when we divide it by 9 it leaves a remainder of 6
since we need a least no. divided by three which also leaves 3 remainder
we put value of k=1, 2, 3.... till we get the required no.
since

Satheesh said:   1 decade ago
Divide each answer by 9 which one has no reminder that's answer.

Chandresh said:   1 decade ago
But concept of finding the value of k is still not clear.

Can anyone tell the concept except logical solution?


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