In Data Interpretation, Data Comparison is the calculation and display of the differences and similarities between data objects. Almost all the competitive examinations test the basic knowledge of facts and skills along with reasoning, analytical and problem solving abilities through the questions on Data Comparison. Through this article, we will equip you with tactics to solve Data Comparison questions in Data Interpretation section efficiently.
What is Data Comparison question like?
A typical question requires you to compare 2 quantities instead of solving for a particular value. Let us delve into detail with the help of an example.
Directions:
Each Data Comparison question consists of 2 quantities, one in column A and one in column B. We have to decide the data given in which column is higher and answer whether,
The 1^{st} 3 choices represent a definite relationship between the quantities in both the columns. But choice D represents a relationship that cannot be determined.
Note 1
Data Interpretation Strategy: How to solve Data Comparison questions?
Example 1: Compare the value of each expression in the 2 columns, given, w>x>0>y>z
Column A | Column B |
w+y | x+z |
Solution: Here, w>x and y>z.
Thus the 1^{st} term in column A is greater than the 1^{st} term in column B. Similarly the 2^{nd} term is greater in column A is greater than the 2^{nd} term in Column B. Now sum of two greater terms will be greater than the lesser terms. Therefore, column A is greater than column B. Option A is the answer.Example 2: Compare the value of each expression in the 2 columns
Column A | Column B |
x(x+2) | x^{2}+2x |
Solution: On expansion, column A is same as that of column B. Hence, we see that the value of both columns is equal. Option C is the answer.
Example 3: Compare the value of each expression in the 2 columns, given 4a+3=7b
Column A | Column B |
20a+10 | 35b-5 |
Solution: Since both the columns are multiples of 5, we can divide both the terms by 5.
It simplifies to 4a+2 in the Column A and 7b-1 in column B. Adding 1 to both columns, Column A = 4a+3 Column B = 7b As given 4a+3=7b, Hence, both the columns are equal. Option C is the answer.Example 4: Compare the value of each expression in the 2 columns, given r>s>k>w>0
Column A | Column B |
r/t | s/w |
Solution: According to the given relation r>s>k>w>0, Let us assign arbitrary values to the 4 variables.
Let r=4, s=3, t=2 and w=1. Now, Column A = r/t = 4/2 = 2 Column B = s/w = 3/1 = 3 Thus column B is greater than column A. Option B is the answer.Note 2: Assign more than 1 value and calculate again to cross check.
Let r=30, s=3, t=2, w=1 r/t = 30/2 = 15, s/w= 3/1=3 Thus column A is greater than column B. Hence, the answer is option DData Comparison: Key Learning