Aptitude - Decimal Fraction - Discussion

In the first three numbers, the difference between the numerator and the denominator are same and the denominator is greater than numerator if there is a condition like this, then if the numerator is lesser, the value is lesser.

These type of problems can be solved by Cross Multiplication principle.

I will try to explain with the present problem scenario

Consider (1/3) and (2/5)

STEP 1: Multiply numerator of 1st with denominator of 2nd
Multiply denominator of 1st with numerator of 2nd

STEP 2: The result is (1*5) and (3*2)
i.e.., 5 and 6
Now Check which number is greater of the two.
In this case 6>5
STEP 3: Check which fraction's numerator is part of the product
that results in greater number(6)

In this case 6 has numerator of 2nd fraction (2/5)
So we can say that (2/5) >(1/3)

SO ON WITH THE NEXT FRACTIONS ALSO

First cross multiply each term with adjacent next term. So we get a number series as follows.

Eg. take option D.

6*6 = 36
7*5 = 35
5*5 = 25
6*4 = 24
4*7 = 28
5*3 = 15
2*3 = 6
1*5 = 5

From this series we clear that it is in descending order.

Thanks @Deepak.

If the numerator is increasing by a constant number the smaller the numerator the smaller the fraction.

@All.

A B and C options start with 1/3.

This means they are in ascending order
only D starts with 6/7,
This is arranged in descending order.
So, D is the answer.

@Shahid your cross multiplication method is great.

For the first three option take the 1st and last digit, then compare the two digit.

For option a), b)and c)
1/3=0.3333 and 6/7=0.8571, now we can see that 1st one is smaller then last one.

So they are not in descending order.

Hence answer is the rest means option D).

Let us check option D.

Write 6/7 = 60/7, 5/6 = 50/6, 4/5 = 40/5, and so on it makes easy to calculate. Since we converted them into improper functions.

8.5, 8.2, 8, 4.2, 4, 3.3

I did it by seeing just observe any numbers with same denominators like I supposed 7 denominator for option A I saw that 3/7 is coming before then 6/7 so option A is not in descending order, like as I tried B & C, lastly I got D which is correct for my consideration.