1000 families with 2 children were selected randomly, and the following data were recorded: `N u m b e r\ of\ boy s\ in\ a\ fa m i l y :` `0` `1` `2` `N u m b e r\ of\ fa m i l i e s :` `140` `560` `300` If a family is chosen at random, find the probability that it has (i) No boy (ii) one boy (iii) 2 boys (iv) at least one boy (v) at most one boy

Explanation

Total number of families=`1000`
(i)Number of families having no boy=`140`
`therefore P("no boy")=140/1000=0.14`
(ii)Number of families having one boy=`560`
`therefore P("one boy")=560/1000=0.56`
(iii)Number of families having two boys=`300`
`therefore P("two boys")=300/1000=0.3`
(iv)Number of families having at least one boy =`560+300=860`
`therefore P("at least one boy")=860/1000=0.86`
(v)Number of families having at most one boy =`560+140=700`
`therefore P("at most one boy")=700/1000=0.7`