NCERT Solution for Introduction to Graphs

(i) What was the patient's temperature at 1 p.m.?

(ii) When was the patient�s temperature 38.5°C?

(iii) The patient's temperature was the same times during the period given. What were two times?

(iv)What was the temperature at 1.30 p.m.? How did you arrive at your answer?

(v) During which periods did the patient�s temperature showed an upwart trend?

(i) The temperature of the patient a: 1 pm 36.5°C.

(ii) The temperature of the patient was 38.5°C at 12 noon.

(iii) The temperature of the patient at 1.30 pm and 2 p.m.

(iv) The temperature of the patient at 1.30 pm was 36.5°C. The point between 1 pm and 2 pm on the x-axis is equidistant from the two points showing 1 pm and 2 pm, so it will represent 1.30 pm. Similarly, the point on the y-axis, between 36°C and 37°C will represent 36.5°C

(v) During the periods 9 am to 10 am, 10 am to 11 am and 2 pm to 3 pm the patients temperature showed an upwards trend.

(i) What-were the sales in (a) 2002 (b) 2006?

(ii) What were the sales in (a) 2003 (b) 2005?

(iii) Compute the difference between the sales in 2002 and 2006.

(iv) In which year was there the greatest difference between the sales as comapred to its previews year?

(i) (a) The sales in the year 2002 is Rs. 4 crore.

(b) The sales in the year 2006 is Rs. 8 crore.

(ii) (a) The sales in the year 2003 is Rs. 7 crore.

(b) The sales in the year 2005 is Rs. 10 crore.

(iii) The difference between the sales in 2002 and 2006 = Rs. 8 crore - Rs. 4 crore = Rs. 4 crore.

(iv) The year in which there was the greatest difference between the sales compared to its previous year is the year 2005.

(a) How high was Plant A after (i) 2 weeks (ii) 3 weeks?

(b) How high was Plant B after (i) 2 weeks (ii) 3 weeks?

(c) How much did Plant A grow during the 3rd weeks?

(d) How much did plant B grow from the end of the 2nd week to the end of the 3rd week?

(e) During which week did Plant A grow maximum ?

(f) During which week did Plant B grow least?

(g) Were the two plants of the same height during any week shown here? Specify.

(a) The height of the plant A after

(i) 2 weeks was 7 cm

(ii) 3 weeks was 9 cm

(b) The height of the plant B after

(i) 2 weeks was 7 cm

(ii) 3 weeks was 10 cm

(c) The plant A grows 2 cm during the 3rd week.

(d) The plant B grows 3 cm from the end of the 2nd week to the end of the 3rd week.

(e) The plant A grows most during second week.

(f) The plant B grows most during first week.

(g) At the end of the 2nd week the heights of the two plants were the same.

(a) On which days was the forecast temperature the same as the actual temperature?

(b) What was the maximum forecast temperature during the week?

(c) What was the minimum actual temperature during the week?

(d) On which day did the actual temperature differ the most from the forecast temperature?

(a) The days on which the forecast temperature was the same as the actual temperature are Thuesday, Friday and Sunday.

(b) The maximum forecast temperature during the week was 35°C.

(c) The minimum actual temperature during the week was 15°C.

(d) The actual temperature differed the most from the forest temperature on Thursday.

(a) The number of days a hill side city received snow in different years.

(b) Population (in thousands) of men and women in a village in different years.

(b) In order to draw the required graph, we represent years on the x-axis and the population (in thousands) on the y-axis. The dotted line shows the population (in thousands) of men and the solid line shows the population (in thousands) of women.

We first plot the ordered pairs (2003,12), (2004,12.5), (2005,13), (2006,13.2) and (2007,13.5) and then join them by the dotted line as shown, to get the graph representing the number of men. Further, we plot (2003, 11.2), (2004, 11.9), (2005, 13), (2006,13.6) and (2007,12.8) and then join them by line segments as shown to get the graph representing the graph of number of women. Thus, the required graph is obtained.

(a) What is the scale taken for the time axis

(b) How much time did the person take for the travel?

(c) How far is the place of the merchant from the town?

(d) Did the person stop on his way ? Explain.

(e) During which period did he ride fastest?

(a) The scale taken for the time axis is:

4 units = 1 hour.

(c) The merchant's place from the town is 22 km.

(d) Yes; this is indicated by the horizontal part of the graph (10 a.m. � 10.30 a.m.)

(e) Between 8 a.m. and 9 a.m. he ride faster.

(ii) This represents a time-temeprature graph because it represent a smooth fall in temeprature and is represented by a line graph.

(iii) This does not represent a time-temperature because it shows different temperatures at the same time.

(iv) This represents a time-temperature graph because it shows a constant temperature at different times and is a line graph.

(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), 145, 3), M(5, 5), N(2, 5).

Clearly, these points lie on a line ABDC.

O (0, 0), A (2, 0), B (2, 3) and C (0, 3);

P (4, 3), Q (6, 1), R (6, 5) and S (4, 7);

L (7, 7), M (10, 8) and K (10, 5).

(i) A point whose x-coordinate is zero and y-coordinate is non-zero will lie on the y-axis.

(ii) A point whose y-coordinate is zero and x-coordinate Is 5 will lie on y-axis.

(iii) The coordinates of the origin are (0,0).

(ii) False. Correct statement is: A point whose y-coordinate is zero and x-coordinate is 5 will lie on X-axis

(iii) True

(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?

Scale: 1 unit = 1 cm on x-axis and y-axis.

Plot the points (2, 8), (3,12), (3.5, 14), (5, 20) and (6, 24), Joip these points to obtain the required graph.

It is a linear graph.

Plot points (2, 4), (3, 9), (4, 16), (5, 25), (6,36) It is not a linear graph.