Introduction to Graphs : Exercise 15.3 (Mathematics NCERT Class 8th)

Q.1 Draw the graphs for the following tables of values, with suitable scales on the axes.
(a) Cost of apples

(b) Distance travelled by a car

(i) How much distance did the car cover during the period 7.30 a.m. to 8 a.m?
(ii) What was the time when the car had covered a distance of 100 km since it’s start?

(c) Interest on deposits for a year.

(i) Does the graph pass through the origin?
(ii) Use the graph to find the interest on Rs 2500 for a year.
(iii) To get an interest of Rs 280 per year, how much money should be deposited?
Sol. (a) The graph for given data is as shown below:
Here, x-axis represents the number of apples and scale taken is 1 unit = 1 apple, whereas y-axis represents cost (in Rs) and scale taken is 1 unit = Rs 5.(b) The graph for given data is as shown below:
Here, x-axis represents the time and scale taken is 2 units = 1 hour, whereas y-axis represents distance (in km) and scale taken is 2 units = 40 km.(i) The car covered distance of 20 km during the period 7.30 a.m. to 8 a.m.
(ii) The time was 7.30 am when the car had covered a distance of 100 km since it’s start.

(c) The graph for given data is as shown below:
Here, x-axis represents the deposit (in Rs) and scale taken is 1 unit = Rs 1000, whereas y-axis represents simple interest (in Rs) and scale taken is 1 unit = Rs 80.(i) Yes, the graph do passes through the origin.
(ii) From the graph, it can be seen that the interest on Rs 2500 for a year is Rs 200.
(iii) Rs 3500 should be deposited to get an interest of Rs 280 per year.

Q.2 Draw a graph for the following.
(i)

Is it a linear graph?
(ii)

Is it a linear graph?
Sol. (i) The graph for given data is as shown below:
Here, x-axis represents the side of square (in cm) and scale taken is 1 unit = 1 cm, whereas y-axis represents perimeter (in cm) and scale taken is 1 unit = 4 cm.Yes, it is a linear graph.
(ii) The graph for given data is as shown below:
Here, x-axis represents the side of square (in cm) and scale taken is 1 unit = 1 cm, whereas y-axis represents area (in cm²) and scale taken is 1 unit = 4 cm².No, it is not a linear graph.