9th MATH

NCERT TEXTBOOK QUESTIONS SOLVED EXERCISE 15.1 1.   In a cricket match, a batswoman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary. Sol.  Here, the total number of trials = 30           Number of times the ball touched boundary = 6           Number of times, the ball missed the boundary = 30 � 6 = 24           Let the event not hitting the boundary be represented by E, then                      Thus, the required probability = 0.8 2.   1500 families with 2 children were selected randomly, and the following data were recorded: Number of girls in a family 2 1 0 Number of families 475 814 211       ...

EXERCISE 14.4 1.    The following number of goals were scored by a team in a series of 10 matches: 2, 3, 4, 5, 0, 1, 3, 3, 4, 3         Find the mean, median and mode of these scores. Sol.  To find mean:         Here, n = 10,                  Thus, the median of the data = 3         To find the mode:         ∵ In the given data               0 occurs 1 time, 1 occurs 1 time, 2 occurs 1 time, 3 occurs 4 times, 4 occurs 2 times,  5 occurs 1 time         ∵ 3 occurs maximum number of times.         ∴ Mode = 3. 2.    In a Mathe...

EXERCISE 14.3 1.    A survey conducted by an organisation for the cause of illness and death among the women between the ages 15 – 44 (in years) worldwide, found the following figures (in %):                  (i) Represent the information given above graphically.         (ii) Which condition is the major cause of women’s ill health and death worldwide?         (iii) Try to find out, with the help of your teacher, any two factors which play a major role in the cause in (ii) above being the major cause. Sol.  (i) The required graphical representation is given below:         (ii) The major cause of women’s ill health and death worldwide is �reproductive health conditions’.         (iii) The two factors are: ...