Chapter 15 Introduction to Graphs
Question 1.
Write the coordinates of each point shown is the graph.
Solution:
Question 2.
From the given figure, choose the letters indicate the location of the points.
(i) (3, 1)
(ii) (0, 5)
(iii) (3, 0)
(iv) (1, 2)
(v) (2, 3)
(vi) (8, 12)
(vii) (6, 10)
(viii) (0, 9) 
Solution:
(i) D(3, 1), (ii) E(0, 5), (iii) F(3, 0), (iv) G(1, 2), (v) H(2, 3), (vi) B(8, 12), (vii) C(6, 10), (viii) A(0, 9)
Question 3.
Draw the graph of the following table. Is it a linear graph? 
Solution: 
Yes, it is a linear graph.
Question 4.
The given graphs show the progress of two different cyclists during a ride. For each graph, describe the rider’s progress over the period of time. (NCERT Exemplar) 
Solution:
(a) As time passes, the speed of cyclist I decreases steadily.
(b) Speed of cyclist II increases for a short time period, and then increases very slowly.
Question 5.
Match the coordinates given in Column A with the items mentioned in Column B. (NCERT Exemplar) 
Solution:
(i) – (d), (ii) – (f), (iii) – (e), (iv) – (a), (v) – (b), (vi) – (c)
Question 6.
The given graph shows the flight of an aeroplanes. 
(i) What are the scales taken on x-axis and y-axis?
(ii) Upto what height the aeroplane rises?
(iii) What was the speed of the aeroplane while rising?
(iv) How long was the plane in level flight?
(v) How long did the whole flight take?
Solution:
(i) Scale on x-axis, 1 cm = 10 minutes
Scale ony-axis, 1 cm = 100 metres
(ii) The aeroplane rose upto 1000 metres.
(iii) The speed of the aeroplane while rising was 100 m per minutes.
(iv) The time taken by the aeroplane to be in level flight is 40 + 30 = 70 minutes
(v) Total flight time is 130 minutes.
Question 7.
A bank gives 10% interest on the deposits by the Ladies. Draw a graph showing the relation between the amount deposited and the simple interest earned by the ladies and state following from the graph.
(i) The annual interest earned for an investment of ₹ 250
(ii) The investment one has to make to get an annual interest of ₹ 70. 
Solution:
Required Graph is as under: 
(i) ₹ 25 is Earned as annual interest for an investment of ₹ 250
(ii) ₹ 700 is to be invested to get an annual interest of ₹ 70.
