27) C

5% own neither phones nor laptops.
So the overlap would be somewhere in the remaining 95%.

Best method to do it:

The minimum
The total percentage is 100%.
Start from 5% and add 55%(minimum of laptop) to it. This gives us 60%. Let the remaining 40% be mobile owners.
Since minimum of mobile = 70% and we have got 40%, the overlap must = 60 – (100 – 70) = 60 – 30 = 30%.
However, the percentage that own neither is actually fewer than 5%, which means that the percentage that own both would be a bit smaller. So 25% is correct.

The maximum
The total percentage is 100%.
Start from 5% and add 65%(maximum of laptop) to it. This gives us 70%. Let the remaining 30% be mobile owners.
Since maximum of mobile = 80% and we have got 30%, the overlap must = 70 – (100 – 80) = 70 – 20 = 50%.

So the range is 25% – 50%

Leave a Reply