In a certain village, 22% of the families own agricultural land, 18% own a mobile phone
In a certain village, 22% of the families own agricultural land, 18% own a mobile phone and 1600 families own both agricultural land and a mobile phone. If 68% of the families neither own agricultural land nor a mobile phone, then the total number of families living in the village is
- 20000
- 10000
- 8000
- 5000
Solution
Let total number of families in the village = x
Number of families own agricultural land, n(A) = 0.22x
Number of families own mobile phone, n(M) = 0.18x
Number of families own both agricultural land and mobile phone, n(A ⋂ M) = 1600
Number of families own agricultural land or mobile phone, n(A ⋃ M) = x - 0.68x = 0.32x
n(A ⋃ M) = n(A) + n(M) - n(A ⋂ M)
n(A ⋂ M) = 0.08x
0.08x = 1600
⇒ x = 20000
The correct option is A.