Aptitude - Decimal Fraction - Discussion

Another shortcut to solve this que is to multiply numerator by 100 and simply dividing it with denominator like this:

100/3=33.3.
200/5=40.
300/7=42.8.
400/5=80.
500/6=83.3.
600/7=85.6.

Then we have the answer.

85.6>83.3>80>42.8>40>33.3.

Answer is 6/7 > 5/6 >4/5 > 3/7 > 2/5 > 1/3.

We can directly opt the first big fraction.

Another simple method:

Lets option A that is:
1/3 , 2/5 , 3/7 , 4/5 , 5/6 ,6/7

Take the LCM of all the denominators which is
3,5,7,5,6,7

LCM is 210
make the denominator 210. The fraction which is
70/210 , 84/210 , 90/210 ,168/210 , 175/210 ,180/210

now we can easily compare the values because all the denominator is same.
So the decending order is:

180/210 , 175/210 ,168/210 ,90/210 ,84/210 , 70/210.

i.e.

6/7 , 5/6 , 4/5 , 3/7 , 2/5 , 1/3.

This is the answer, it is very short to solve, hope now you will got it.

By carefully watching this particular problem, we can observe that the option A,B & C numerators are in ascending order whereas the option D numerator are given in descending order.

Please explain answer.