Question

(i) There are 30 cards of the same size, in a bag on which numbers 1 to 30 are written. One card is taken out of the bag at random. Find the probability that the number on the selected cards is not divisible by 3.
(ii) If the probability of an event E, i.e., P (E) is 0.08, what would the probability of the event ‘not E’ be?
(iii) In a group of 3 students, the probability of 2 students not passing an examination is 0.895. Find the probability of the 2 students passing the examination.

Answer 1

Answer:

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Q.1 )

Numbers divisible by 3 = 3,6,9,12,15,18,21,24,27,30

P (E ) = 20 / 30

= 10 / 15

= 2 / 3

Q.2 )

P ( E) = 0.08

P ( not E ) = 1 - P (E )

= 1 - 0.08

= 0.98

Q.3 )

P ( not passing ) = 1 - P ( passing )

= 1 - 0.895

= 0.215

Answer 2

Answer:

$\huge\fcolorbox{black}{pink}{Answer-}$

1 )

numbers divisible by 3 = 3 ,6,9,12,15,18,21,24,27,30

total outcomes = 30 - 10

= 20

P ( not divisible by 3 ) = 20 / 30

= 2 / 3

2 )

P( not E ) = 1 - P( E )

= 1 - 0.08

= 0.92

3 )

P ( 2 passing ) = 1 - 0.895

= 0.105