PROBLEMS ON LINE GRAPH

Problem 1 :

Below is a line graph that shows how many books are sold in a charity shop over one week.

(a) On which day did the charity shop sell the most books?

(b) On which day did the charity shop sell the least books?

(c) How many books were sold on Tuesday?

Solution :

a) By observing the graph, on Thursday most number of books sold out.

b)  On Saturday, least number of books sold out.

c)  On Tuesday, 80 books were sold out.

Problem 2 :

Below is a line graph that shows the population of a village.

(a) What was the population in 1980?

(b) In which year was the population 700?

Solution :

a) On 1980, the population is 750.

b) On 1970 the population was 700.

Problem 3 :

Analyze the line graph, complete the data table and answer the questions.

1) Complete the data table

2) In which month was the average temperature 30 degrees Celsius?

3) In which 2 months was the average temperature the same?

4) In which months was the average temperature higher than 20 degrees?

5) How much did the average temperature increase between January and April?

Solution :

1) 

2) On the month of May, the average temperature 30 degrees Celsius

3) In the months February and March, the average temperatures are same.

4)  The average average temperature in the month of May and June are more than 20 degree.

5) Increase between Jan and April is 20 - 10 = 10

Problem 4 :

This graph shows the temperature in °C from 2 am to 3 pm on a cold day

a) How many degrees warmer was it at 3 pm than at 3 am?

b) At 6 pm the temperature was 4 degrees lower than at 3 pm. What was the temperature at 6 pm?

Solution :

a) Temperature at 3 am = -5°C

Temperature at 3 pm = 2°C

= |-5| + |2|

= 5 + 2

= 7

So, on that cold day the temperature is 7°C warmer at 3 pm than at 3 am.

b) At 3 pm, the temperature = 2°C

Temperature at 6 pm = 2 - 4

= -2°C

Problem 5 :

This graph shows the height of a balloon at different times.

a) From the graph, find the height of the balloon at 50 seconds.

b) Use the graph to find how long it took the balloon to rise from 30 meters to 60 meters

Solution :

a) the height of the balloon 47 m at 50 seconds.

b) At 30 meters = 25 seconds

At 60 meters = 50 seconds

= 50 - 25

= 25 seconds

Problem 6 :

This chart shows the population of Cornwall from 1950 to 2010.

a) In which year did the population first reach 400000?

b) How much did the population increase from 1950 to 2000?

c) What was the population of Cornwall in 2010?

Solution :

a) The population reaches 400000 at 1985.

b) Population at 2000 = 500000

Population at 1950 = 350000

Increase in population = 500000 - 350000

= 150000

c) Population of Cornwall in 2010 = 510000

Problem 7 :

This graph shows the outside temperature from 4pm to 10pm on a day in winter.

a) At what time was the temperature –2°C?

b) How many degrees did the temperature drop from 5 pm to 7 pm?

Solution :

a) At 8.45 pm the temperature –2°C

b) Temperature at At 5 pm = 2°C

Temperature at At 7 pm = -1°C

= |2} + |-1|

= 2 + 1

= 3

So, the temperature drops 3°C.

Problem 8 :

This graph shows how the weight of a baby changed over twelve months.

a) From the graph, what was the weight of the baby at 10 months?

b) How much more did the baby weigh at 5 months than at birth?

Solution :

a) Weight of baby at 10 months is 8.75 kg.

b) The weight of baby when it born = 3.75 kg

Weight of baby after 5 months = 7

Difference between the weights = 7 - 3.75

= 3.25 kg

Problem 9 :

This chart gives the cost of showing advertisements on television at different times.

a) An advertisement lasts 25 seconds. Use the graph to estimate how much cheaper it is to show it in the daytime compared with the evening.

An advertisement was shown in the daytime and again in the evening.

The total cost was £1200

b) How long was the advertisement in seconds?

Solution :

a)  

For 25 minutes advertisement,

• the cost is $575 in the day time
• the cost is $1100 in the evening

b) For $1200, the length of advertisement is 30 seconds.

Problem 10 :

This graph shows the cost of phone calls in the daytime and in the evening.

a) How much does it cost to make a 9 minute call in the daytime?

b) How much more does it cost to make a 6 minute call in the daytime than in the evening?

Solution :

a) The cost of 9 minute call in the day time is 47 p

b) Cost for 6 minute call in the daytime = 30p

Cost for 6 minute call in the evening = 10 p

Difference = 30 - 10

= 20 p