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. 13)
13.
| Reduce | 128352 | to its lowest terms. |
| 238368 |
Answer: Option
Explanation:
128352) 238368 ( 1
128352
---------------
110016 ) 128352 ( 1
110016
------------------
18336 ) 110016 ( 6
110016
-------
x
-------
So, H.C.F. of 128352 and 238368 = 18336.
128352 128352 ÷ 18336 7
Therefore, ------ = -------------- = --
238368 238368 ÷ 18336 13
Discussion:
59 comments Page 2 of 6.
Pankaj said:
1 decade ago
Please somebody answer why after we have to stop subtracting after.
18336?
18336?
Vanaja said:
1 decade ago
@Sona thanks.
Seema said:
1 decade ago
Check the ones digit of numerator & denominator. It must come in the table of answer digit at ones place. It will fewer your option.
Then check numerator is fully divided by numerator & denominator by denominator.
Then check numerator is fully divided by numerator & denominator by denominator.
Ammu said:
1 decade ago
We have to stop subtracting when the result becomes negative.
128352-110016 = 18336.
18336-110016 = negative number.
128352-110016 = 18336.
18336-110016 = negative number.
Rosy said:
1 decade ago
238368-128352 = 110016.
128352-110016 = 18336.
110016-18336 = 91680.
18336-91680 = (negative, so not taken).
If we do 238362/91680 = 2.6(in decimal, so not taken).
And 128352/91680 =1.4 this too.
So now, take 128352/18336 = 7 and 238368/18336 = 13.
Two are integers, not in decimals.
So we take this value friends.
Now answer is 7/13.
128352-110016 = 18336.
110016-18336 = 91680.
18336-91680 = (negative, so not taken).
If we do 238362/91680 = 2.6(in decimal, so not taken).
And 128352/91680 =1.4 this too.
So now, take 128352/18336 = 7 and 238368/18336 = 13.
Two are integers, not in decimals.
So we take this value friends.
Now answer is 7/13.
Shraddha said:
1 decade ago
Find the factors of 128352.
Then find the factors of 238368.
Cancel out the common factors.
It leads to the ratio of uncommon factors, i.e. 7/13, which is the lowest ratio.
Then find the factors of 238368.
Cancel out the common factors.
It leads to the ratio of uncommon factors, i.e. 7/13, which is the lowest ratio.
Ambica said:
1 decade ago
Why are we subtracting?
Soumen said:
1 decade ago
Simple check option A.
3*1 = 3....128352 not match the last number i.e. 3&2.
3*2 = 6....128352 not match the last number i.e. 3&2.
...
3*4 = 12...128352 now match the last number i.e. 2&2.
Now 4*4 = 16...238368 not match the last number i.e. 6&8.
Check option C.
7*6 = 42....128352 now match the last number i.e. 2&2.
Now 13*6 = 78...238368 now match the last number i.e. 8&8.
3*1 = 3....128352 not match the last number i.e. 3&2.
3*2 = 6....128352 not match the last number i.e. 3&2.
...
3*4 = 12...128352 now match the last number i.e. 2&2.
Now 4*4 = 16...238368 not match the last number i.e. 6&8.
Check option C.
7*6 = 42....128352 now match the last number i.e. 2&2.
Now 13*6 = 78...238368 now match the last number i.e. 8&8.
Sandeep said:
1 decade ago
Hey, someone check option A.
You have checked---as-3*4 = Match the last number.
But why dint you check 4*2 this also match the last no 238368--match found, but option A is not true.
You have checked---as-3*4 = Match the last number.
But why dint you check 4*2 this also match the last no 238368--match found, but option A is not true.
Shravani janadri said:
10 years ago
It can be solved even more efficiently.
Since we have 13 in denominator among options.
238368/13 = 18336.
Now Cross check options to know unit place value.
18336*7=_______2.
18336*5=_______0.
18336*9=_______9.
And the numerator has 2 In units place so go with option 7/13.
This always works if we don't have non of the above as option.
Since we have 13 in denominator among options.
238368/13 = 18336.
Now Cross check options to know unit place value.
18336*7=_______2.
18336*5=_______0.
18336*9=_______9.
And the numerator has 2 In units place so go with option 7/13.
This always works if we don't have non of the above as option.
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