Question

In a town of `10,000` families, it was found that `40%` of the families buy newspaper `A`, `20%` buy newspaper `B`, `10%` buy newspaper `C`, `5%` buy `A` and `B`, `30%` buy `B` and `C` and `4%` buy `A` and `C`. If `2%` buy all the three newspapers, find the number of families which buy.
(i) A only,
(ii) B only,
(iii) none of A, B and C.

Answer 1

Correct Answer - (i) 3300
(ii) 1400
(iii) 4000
`n(A) =(40% of 10000) =((40)/(100) xx10000)=40000`,
` n(B) =(20% Of 10000)=2000, n(C) =(10%of 10000) =1000`,
`n( A cap B) =(5% of 10000)= 500, n( B cap C)= (3% of 10000) =300`,
` n( A cap C) =(4% of 10000) =4000, n(A cap B cap C) =(2% of 10000) =200`,
and ` n(U) =10000`,
`{(a+b+c+d,=4000","),(b+c+e+f,=2000","),(c+d+f+g,=1000","),(" "b+c,=500","),(" "c+f,=300","),(" "c+d,=400","),(" "c,=200","):}`