Q63 of 66 Page 15

A game of chance consists of spinning an arrow on a circular board, divided into 8 equal parts, which comes to rest pointing at one of the numbers 1, 2, 3, …, 8 (Fig. 9), which are equally likely outcomes. What is the probability that the arrow will point at (i) an odd number (ii) a number greater than 3 (iii) a number less than 9.

 [CBSE 2016]

From the figure, we have

Total numbers = 8


(i) Total Odd numbers = 1, 3, 5, 7 = 4


∴



(ii) Total numbers greater than 3 = 4, 5, 6, 7, 8 = 5



(iii) Total numbers less than 9 = 1, 2, 3, …8 = 8


∴


= 1

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