Ex.15.1 Q1 Introduction to Graphs Solutions - NCERT Maths Class 8

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The following graph shows the temperature of a patient in a hospital, recorded every hour.

(a) What was the patient’s temperature at \(1\;\rm{pm}\)?

(b) When was the patient’s temperature \(38.5^\circ\rm{C}\)?

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

(d) What was the temperature at \(1.30\;\rm{pm}\)? How did you arrive at your answer?

(e) During which periods did the patient’s temperature show an upward trend?

 Video Solution
Introduction To Graphs
Ex 15.1 | Question 1

Text Solution


Horizontal axis represents Time and vertical represents Temperature in \(^\circ\,\rm{C.}\)

We can find the value of ‘Temperature’ on vertical axis according to the given value of ‘Time’ on the horizontal axis value or vice versa.


(a) At \(1\;\rm{ pm}\) the patient’s temperature was \(36.5^\circ\,\rm{ C.}\)

(b) The patient’s temperature was \(38.5^\circ\,\rm{ C}\) at \(12\) noon.

(c) The patient’s temperature was \(36.5^\circ\rm{C}\)  at \(1 \,\rm{pm}\) and \(2 \,\rm{pm.}\)

(d) The graph between the times \(1 \,\rm{pm}\) and \(2 \,\rm{pm}\) is parallel to the x-axis. The temperature at \(1 \,\rm{pm}\) and \(2 \,\rm{pm}\) is \(36.5^\circ \;\rm{C.}\) So, the temperature at \(1.30 \;\rm{pm}\) is \(36.5^\circ \;\rm{C.}\)

(e) During \(9 \)am to \(10 \;\rm{pm}\), \(10 \;\rm{pm}\) to \(11 \;\rm{pm}\), \(2\;\rm{pm}\)  to \(3\;\rm{pm}\) , the patient’s temperature showed an upward trend. 

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