Tips to Quickly Solve Line Graphs in Data Interpretation Section

What is a Line Graph?

A modified version of Bar Graph representation is said to be a Line Graph. On connecting the upper points of two adjacent Bars of a Bar Graph we get a line and on further repeating this procedure with other Bars we get a Line Graph representation.

Solving a Line Graph question

Problems based on line graphs appear frequently in competitive exams having data interpretation as a component. Given below is a popular type of question asked from line graphs:

Check your conceptual clarity in Data Interpretation Line graphs by taking this test now!

DIRECTIONS: Study the following graph carefully and answer the questions given below.

Example 1: In which of the following years was the percentage increase in income over the previous year the maximum?

1. 1989

2. 1990

3. 1991

4. 1992

Solution: Percentage increase= 100 × Increase/Previous year income. Option 3 is eliminated because there’s a decrease in income in 1991.

In 1989, percentage increase = 100 × 20/30 = 66.67%.

In 1990, percentage increase = 100 × 15/50 = 30%.

In 1992, percentage increase = 100 × 17.5/57.5 = 30.43%

(All the data is in Rs '00 cr.) Thus, Option 1 is the answer.

Alternatively,

For maximum % change, numerator should be the greatest and the denominator should be smallest. The numerator for 1989 is the greatest, while the denominator for the same year is the lowest as compared to corresponding figures for 1990 and 1992. So, you need not to find the exact percent increase of all the options given. Hence, answer is 1^st option.

Example 2: What was the average income of the company over the years (approximately)?

1. 4500 cr

2. 500 cr

3. 5500 cr

4. 550 cr

Solution: Average in Rs '00 cr. = (30 + 50 +65 + 55 + 75 + 55)/6 = 55 =>Average= Rs 5500 cr. Hence, answer is 3^rd option.

Example 3: What is the ratio of income to expenditure in the year 1990?

1. 1.2

2. 1.3

3. 1.1

4. 1.4

Solution: The income in the year 1990 is Rs. 6500 cr. and the expenditure is Rs. 5000 cr. Thus, the ratio in the year 1990 will be 6500/5000 = 1.3. Hence, answer is 2^nd option.

Example 4: The total expenditure in 1988 and 1989 together was equal to the income in which of the following years?

1. 1900

2. 1991

3. 1993

4. None of these

Solution: The total expenditure in 1988 and 1989 together = Rs. 6000cr, which does not match with any other year's expenditure. So, the correct answer will be Option 4.

How ready are you to solve Line graph questions now? Take this test to find out.

Key Learning

It is imperative to be fast in approximations and calculations for excelling in questions on Line Graphs.
Questions on Line Graphs have occurred frequently in almost all competitive exams, hence, the more you practice, the better you will be.

For any query about the topic or any other information, do write in the comment box given below.