#### Solved Examples and Worksheet for Interpreting Histograms

Q1Arthur has recorded the number of trucks that crossed a bridge every 2 minutes. Find the total number of trucks that crossed the bridge in first 4 min.

A. 9
B. 12
C. 18
D. 8

Step: 1
From the bar graph, compare the height of bar with the scale on the left.
Step: 2
The bar above 0-2 minutes is on 6 on the scale.
Step: 3
The bar above 2-4 minutes is on 3 on the scale.
Step: 4
The number of trucks that crossed the bridge in the first 4 minutes = number of trucks that crossed the bridge from 0-2 minutes + number of trucks that crossed the bridge from 2-4 minutes
Step: 5
= 6 + 3
[Substitute the values.]
Step: 6
= 9
Step: 7
The total number of trucks that crossed the bridge in the first 4 minutes is 9.
Q2The histogram shows the age groups of working women in a place. Find the number of working women in the age group of 26 - 28 years.

A. 230
B. 210
C. 190
D. 170

Step: 1
The height of each bar in the histogram indicates the number of working women in the corresponding age group.
Step: 2
Number of working women in the age group of 26 - 28 years = number of women in the age group of 26 - 27 years + number of women in the age group of 27 - 28 years
Step: 3
From the histogram, the number of working women in the age group of 26 - 27 years = 90
[The height of the bar representing 26 - 27.]
Step: 4
The number of working women in the age group of 27 - 28 years = 100
[The height of the bar representing 27 - 28.]
Step: 5
Number of women in the age group of 26 - 28 years = 90 + 100 = 190
Step: 6
So, the number of working women in the age group of 26 - 28 years is 190.
Q3The line graph shows the profit a company made in 4 years. Find the profit in the year 2003.

A. $3 million B.$5 million
C. $4 million D.$2 million

Step: 1
Each point on the graph indicates the profit the company made in the corresponding year.
Step: 2
From the line graph, we learn that the profit the company made in the year 2003 is $3 million. Correct Answer is :$3 million
Q4During which period, was the exports quantity the highest?

A. 2000-01
B. 2001-02
C. 2003-04
D. 1999-2000

Step: 1
From the histogram, The height of the bar during the period 2001-02 is maximum.
Step: 2
So, the exports quality is highest during the period 2001-02 .
Q5The histogram shows the number of directors and the number of movies they direct in a year. How many more directors made 2 to 4 movies than those who made 6 to 8 movies ?

A. 10
B. 20
C. 5
D. 15

Step: 1
The height of each bar in the histogram indicates the number of directors who has completed respective number of movies in the year.
Step: 2
From the graph, the number of directors who made 2 to 4 movies in the year is 20.
Step: 3
The number of directors who made 6 to 8 movies in the year is 10.
Step: 4
The difference between the two numbers = 20 - 10 = 10
[Subtract 10 from 20.]
Step: 5
So, 10 more directors made 2 to 4 movies in the year than those who made 6 to 8 movies.
Q6According to the graph below, which is a valid statement?

A. More than 50% of the students scored above 80.
B. More students had scores of 40 or below.
C. More than 50% of the students scored below 60.
D. More students scored 60 - 80 than 80 - 100.

Step: 1
Consider each choice listed. Interpret each choice and compare with the graph shown.
Step: 2
Among the choices, ′more students scored 60 - 80 than 80 - 100′ is a valid statement.
Correct Answer is :   More students scored 60 - 80 than 80 - 100.
Q7A box contains green, red, black and pink colored candles. The numbers of each colored candles are recorded on a bar graph. Name the color which had lowest number of candles.

A. Pink
B. Green
C. Red

Step: 1
The height of a bar in the bar graph represents the number of candles of that particular color.
Step: 2
The bar representing the candles in pink color is the smallest than all the other bars.
Step: 3
So, the pink colored candles are lowest in number.
Q8A survey shows number of employees who retired from an industry and the results are shown in the histogram. How many employees retired during the period 1990-1998?

A. 650
B. 900
C. 750

Step: 1
From the graph, the number of employees retired from 1990-92 is 250.
Step: 2
From the graph, the number of employees retired from 1992-94 is 200.
Step: 3
From the graph, the number of employees retired from 1994-96 is 300.
Step: 4
From the graph, the number of employees retired from 1996-98 is 150.
Step: 5
So, the number of employees retired from 1990-98 = 250 + 200 + 300+ 150 = 900.
Q9The histogram shows the working hours of employees in a company. Find the number of employees working in between 4 to 7 hours.

A. 5
B. 6
C. 2
D. 4

Step: 1
Number of employees working in between 4 to 7 hours = Height of the rectangle corresponding to the class interval 4 - 7
[Height of each rectangle represent the frequency of each class.]
Step: 2
= 6

Step: 3
So, 6 employees work in between 4 to 7 hours..
Q10The graph shows the number of students and their respective scores in a test. Find the number of students who scored in between 84 and 100.

A. 10
B. 12
C. 6
D. 8

Q11The histogram shows the daily wages (in Rs) of 18 workers. How many workers receive more than Rs 70 ?

A. 7
B. 4
C. 3
D. 1

Step: 1
The height of each bar on the histogram tells us how many workers receive the corresponding wages in dollars.
Step: 2
Number of workers who receive more than Rs 70 = Number of workers whose wages is between Rs 70 - 75 + Number of workers whose wages is between Rs 75 - 80
Step: 3
= 3 + 1 = 4
Step: 4
Therefore, 4 workers receive more than Rs 70.
Q12A shopkeeper bought 10 boxes of apples. All boxes contained rotten apples. The histogram represents the data. How many boxes had 4 - 6 rotten apples ?

A. 1
B. 2
C. 4
D. 3

Step: 1
The height of each bar on the histogram tells us the number of boxes in which the corresponding range of rotten apples were found.
Step: 2
The bar above the range 4-6 reaches 4 on the scale.
Step: 3
Therefore, 4 boxes had 4 - 6 rotten apples.