# In a town of 10000 families, it was found that 40% families buy product A, 20% buy product B

#### DAVV MBA PYQ

In a town of 10000 families, it was found that 40% families buy product A, 20% buy product B and 10% buy product C, 5% buy product A and product B, 3% buy product B and product C and 4% buy product A and product C. If 2% families buy product A, B, C all. Then find the number of the families buy product A only.
Solution:
Formula:
n(A U B U C) = n(A)+n(B)+n(C)-n(A ∩ B)-n(A ∩ C)-n(B ∩ C)+n(A ∩ B ∩ C)
Given,
n(A U B U C) = 10000
n(A) = 4000
n(B) = 2000
n(C) = 1000
n(A ∩ B ∩ C) = 200
n(A ∩ B) = 500
n(A ∩ C) = 400
n(B ∩ C) = 300
Number of the families buy product A only ?
From the Venn diagram,
Number of the families by product A only = 3300.

#### Practice questions (DAVV MBA PYQs):

Q1. In a city there are 100000 people, 64% of them speak Greek, 55% people speak Latin, 43% people speak French, 21% people speak both Greek and Latin, 31% people speak both Greek and French, and 41% people speak both Latin and French. Determine the number of people speak all the three languages.