Important questions with solutions for Class 8 Maths Chapter 15 (Introduction to Graphs) has been provided here by our subject experts. The extra questions are available here to help students score better marks in final exam 2020. The materials provided at BYJU’S for CBSE students are as per the latest syllabus and in reference with NCERT book.
In this chapter, students will go through plotting the graph for the different given situations. For example, change in temperature with respect to the number of days can be plotted in an XY plane. The problems and solutions for graphs will consist of such scenarios. To prepare for Maths exam practice Class 8 Maths Important questions for all the chapters here.
Also Check:
 Important 2 Marks Questions for CBSE 8th Maths
 Important 3 Marks Questions for CBSE 8th Maths
 Important 4 Marks Questions for CBSE 8th Maths
Important Questions With Solutions For Maths Class 8 Chapter 15 (Introduction to Graphs)
Q.1: The following line graph shows the yearly sales figures for a manufacturing company.
(a) What were the sales in (i) 2002 (ii) 2006?
(b) What were the sales in (i) 2003 (ii) 2005?
(c) Compute the difference between sales in 2002 and 2006.
(d) In which year was there the greatest difference between the sales as compared to its previous year?
Solution:
(a) The sales in (i) 2002 were Rs. 4 crores and (ii) 2006 was Rs. 8 crores
(b) The sales in (i) 2003 was Rs. 7 crores and (ii) 2005 was Rs.10 crores.
(c) The difference of sales in 2002 and 2006 = Rs. 8 crores – Rs. 4 crores = Rs. 4 crores
(d) In the year 2005, there was the greatest difference between the sales and compared to its previous year, which is (Rs. 10 crores – Rs. 6 crores) = Rs. 4 crores.
Q.2: Use the tables below to draw linear graphs:
(a) The number of days a hillside city received snow in different years.
Year  2003  2004  2005  2006 
Days  8  10  5  12 
(b)Population (in thousands) of men and women in a village in different years.
Year  2003  2004  2005  2006  2007 
No. of men  12  12.5  13  13.2  13.5 
No. of women  11.3  11.9  13  13.6  12.8 
Solution:
a) Consider “Years” along the xaxis and “Days” along the yaxis. Using the given information, the linear graph will look like:
b) Consider “Years” along the xaxis and “No. of Men and No. of Women” along the yaxis (2 graphs). Using the given information, the linear graph will look like:
Q.3: Plot the point (4, 3) on a graph sheet. Is it the same as the point (3, 4)?
Solution:
Locate the x, y axes, (they are actually number lines!). Start at O (0, 0). Move 4 units to the right; then move 3 units up, you reach the point (4, 3). From Fig 15.13, you can see that the points (3, 4) and (4, 3) are two different points.
Q.4: Plot the following points on a graph sheet. Verify if they lie on a line:
(a) A(4,0), B(4, 2),C(4,6), D(4, 2.5)
(b) P(1, 1), Q(2, 2), R(3,3), S(4, 4)
(c) K(2, 3), L(5, 3), M(5,5), N(2, 5)
Solution:
Plot all the points on the graph.
(a) All points A, B, C and D lie on a vertical line.
(b) P, Q, R and S points also make a line. It verifies that these points lie on a line.
(c) Points K, L, M and N do not lie in a straight line
Q.5: Draw the line passing through (2,3) and (3,2). Find the coordinates of the points at which this line meets the xaxis and yaxis.
Solution:
Graph for the Line passes through points (2, 3) and (3, 2) is:
The coordinates of the points at which this line meets the xaxis at (5, 0) and Y axis at (0, 5).
Q.6: Draw the graphs for the following table of values, with suitable scales on the axes.
Interest on deposits for a year.
Deposit (in Rs.)  1000  2000  3000  4000  5000 
Simple interest (in Rs.)  80  160  240  320  400 
(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?
Solution:
Represent “Deposit” on yaxis and “simple interest” on xaxis.
(i) Yes, the graph passes through the origin.
(ii) Interest on Rs. 2500 is Rs. 200 for a year.
(iii) Rs. 3500 should be deposited for the interest of Rs. 280
Extra Questions For Class 8 Maths Chapter 15

 Plot the following points and verify if they lie on a line. If they lie on a line, name it.
(i) (0, 2), (0, 5), (0, 6), (0, 3.5)
(ii) A (1, 1), B (1, 2), C (1, 3), D (1, 4)
(iii) K (1, 3), L (2, 3), M (3, 3), N (4, 3)
(iv) W (2, 6), X (3, 5), Y (5, 3), Z (6, 2)

 State whether True or False. Correct that is false.
(i) A point whose x coordinate is zero and ycoordinate is nonzero will lie on the yaxis.
(ii) A point whose y coordinate is zero and xcoordinate is 5 will lie on yaxis.
(iii) The coordinates of the origin are (0, 0)

 A bank gives 10% Simple Interest (S.I.) on deposits by senior citizens. Draw a graph to illustrate the relation between the sum deposited and simple interest earned. Find from your graph
(a) the annual interest obtainable for an investment of ` 250.
(b) the investment one has to make to get an annual simple interest of ` 70.

 Draw a graph for the following.
Side of the square(in cm)  2  3  3.5  5  6 
Perimeter (in cm)  8  12  14  20  24 
Is it a linear graph?
5. Write the coordinates of each point shown is the graph.