Net Diagram in interpretation

This type of graph indicates the variation of a quantity with respect to two parameters represented on x -axis and y -axis respectively. So the candidate must carefully observe the peaks and depths of the graph to interpret the data.

Example 1:

1. Which year of the following did California have the least number of cases?
A. 1960     
B. 1975    
C. 1970     
D. 1980    
E. 1990
Answer : B
Explanation : From the diagram its 1975

2. How many cases were registered in NY and CAL in 1950?
A. 275      
B. 325      
C. 320     
D. 290      
E. 150
Answer : A
Explanation : 150+125=275

Example 2:
Graph shows expenditure on arms by different countries (value in dollars '000 millions)

1. The amount spent by country C in 1983 is what percentage more than the amount spent by Countries A and B together in 1977? (Find approximately)
A. 50%         
B. 179%     
C. 75%      
D. 13%          
E. 70%
Answer : C
Explanation : The amount spent in 1977 by Countries A and B together =$ (0.75+1.25) = $2.0 million.
The amount spent by Country C in 1983 = $3.5 million.
This is $1.5mn more than (A + B). In percentage it is = (1.5/2.0) (100)=75%.
Therefore the answer is (C).

2. Which of the following statements must be true?
i) Country A spends minimum amount of its budget on arms.
ii) Throughout, Country C has spent the maximum amount on arms during the years shown.
iii) An examination of the information for the last 3 years reveals that generally all 3 countries are reducing their expenditure on arms.

A. i only.        
B. i and ii only     
C. i and iii only         
D. ii and iii only          
E. None of the statements above.
Answer : E
Explanation : From the given data we cannot say the statement i) must be true.

The graph gives us information only about how much money each country is spending on arms, but it does not give us any information of the budget of each country.

Statement ii) is not true. In 1979 Country B has spent more than Country C.
Statement iii) is also not true.

Countries B and C have reduced their expenditure on arms from 1981-83 and country A has reduced its expenditure in 1983 compared to 1982. But in 1982, country A has not reduced its expenditure and is spending the same amount as in 1981. Therefore None of the statement must be true.
Therefore the answer is (E)