Question

According to a survey, at least 65% of the people like BlackBerry, 75% like iPhone and 80% like Samsung. It is known that everyone in the survey likes atleast one of these three. What is the minimum percentage of people who like all three?

• A. 10%
• B. 15%
• C. 20%
• D. 25%

Answer 1

The correct option is C

20%

Let total number of people = X = 100.
No. of people who like BlackBerry = 65
No. of people who like iPhone = 75
No. of people who like Samsung = 80
Now, we need to find III${}_{min}$ which represents the minimum percentage of people who like all three.
III${}_{min}$ = 100 - ((X-65) + (X-75) + (X-80))
Therefore, III${}_{min}$ = 100 - 35 - 25 - 20 = 20.
Thus, required answer = 20%.