Q16 of 55 Page 623

In a survey of 100 families having 2 or less boys. The following data was obtained:















Number of boys in a family



0



1



2



Number of families



18



46



36



If one of the given families is chosen at random, what is the probability that the chosen family has


(i) 1 boy? (ii) 2 boys? (iii) no boy?

Total number families surveyed = 100


Number of families having no boys = 18


Number of families having one boy = 46


Number of families having two boys = 36


Probability P() =


(i) Probability of family having one boy


P(one boy) =


(ii) Probability of family having 2 boys


P(two boy) =


(iii) Probability of family having no boy


P(no boy) =


More from this chapter

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14

Marks obtained by 90 students of Class IX in a test are given below:



















Marks



0-20



20-40



40-60



60-80



80-100



No of students



8



15



32



26



9



Out of these students one is chosen at random. Find the probability that the chosen student obtains


(i) less than 20% marks (ii) 80% of more marks


(iii) 60% or more marks

 15

The blood group of 30 students of a class were recorded as under:

















Blood Group



A



B



AB



O



No of students



9



11



4



6



If a students of this class is chosen at random, What is the probability that the chosen students has blood group


(i)0? (ii) A? (iii) AB?

 17

A die is thrown 100 times and following observations were recorded:





















Outcomes



1



2



3



4



5



6



Frequency



12



18



14



26



14



16



If a die is thrown at random, find the probability of getting


(i) a number less than 3? (ii) a number greater than 4 (iii) an even number

 18

A survey of 600 students about their liking on coffee was conducted and recoded as under:













Opinion



Like



Dislike



No of students



360



140



Out of these students one is chosen at random. What is the probability that the chosen student


(i) likes coffee? (ii) dislikes coffee?