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. 4)
4.
Let N be the greatest number that will divide 1305, 4665 and 6905, leaving the same remainder in each case. Then sum of the digits in N is:
4
5
6
8
Answer: Option
Explanation:

N = H.C.F. of (4665 - 1305), (6905 - 4665) and (6905 - 1305)

  = H.C.F. of 3360, 2240 and 5600 = 1120.

Sum of digits in N = ( 1 + 1 + 2 + 0 ) = 4

Discussion:
158 comments Page 5 of 16.

Kezang Wanhchuk said:   5 years ago
@All.

The solution is;

=> 1305/4= remiander is .250, 4664/4= .250 and 6905/4= .250
1305/5= no remainder to all.
=> 1305/6= .50, 4665/6= .50 and 6905/6= .833(remainder is diferent)
=> 1305/8= .125 so, remainder is less.
Whereas we are finding HCF so less remainder is not HCF.
(1)

Elissa said:   4 years ago
I understood well, thanks to all for explaining.
(1)

Krishna kumar said:   1 decade ago
Sorry I can't understand why we are taking H. C. F. Of (4665 - 1305) , (6905 - 4665) and (6905 - 1305).

Priya said:   1 decade ago
Upto my understanding
(4665 - 1305)=3360, (6905 - 4665)=2240 and (6905 - 1305)=5600
3360:2240:5600
1120:1120:1120

So, Sum of digits in N = ( 1 + 1 + 2 + 0 ) = 4
Hope so,if am wrong means correct me

Prashanthi said:   1 decade ago
1120*3=3360
1120*2=2240
1120*5=5600

the highest common factorial num is:1120 for all 3 numbers
so that here 1+1+2+0=4 we got.....

SWARNA said:   1 decade ago
How we know by seeing the numbers the H.C.F ?

Neha said:   1 decade ago
Thanx priya.

Jinx said:   1 decade ago
Thanks sarsu.

Vishal said:   1 decade ago
Thanks saraswati.

Swati said:   1 decade ago
Why we are taking the HCF of (4665 - 1305) , (6905 - 4665) and (6905 - 1305).

Plzzz explain.


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