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1500 Families with 2 Children Were Selected Randomly, and the Following Data Were Recorded - CBSE Class 9 - Mathematics

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Question

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

Compute the probability of a family, chosen at random, having

(i) 2 girls (ii) 1 girl (iii) No girl

Also check whether the sum of these probabilities is 1.

Solution

Total number of families = 475 + 814 + 211

                                    = 1500

(i) Number of families having 2 girls = 475

`P_1"(a randomly chosen family has 2 girls) "="Number of families having 2 girls"/"Total number of families"=475/1500=19/60`

 

(ii) Number of families having 1 girl = 814

`P_2"(a randomly chosen family has 1 girl) "="Number of families having 1 girl"/"Total number of families"=814/1500=407/750`

 

(iii) Number of families having no girl = 211

`P_3"(a randomly chosen family has no girl) "="Number of families having no girl"/"Total number of families"=211/1500`

 

`"Sum of all these probabilities "=19/60+407/750+211/1500`

                                               `=(475+814+211)/1500`

                                              `=1500/1500=1`

Therefore, the sum of all these probabilities is 1.

  Is there an error in this question or solution?

APPEARS IN

 NCERT Solution for Mathematics Class 9 (2018 to Current)
Chapter 15: Probability
Ex. 15.10 | Q: 2 | Page no. 284

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Solution 1500 Families with 2 Children Were Selected Randomly, and the Following Data Were Recorded Concept: Probability - an Experimental Approach.
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