In the Database H, a max of how many persons can be there such that for each of them, the data on exactly five of the six features is available?
40000
For Database H, total number of entries =1,00,000
We will represent the number of people (in percentage terms) whose data is available by lines as shown in the figure.
As the maximum of 5 out of 6 is asked, we will first consider the 5 details with maximum number of people.
Starting with Name, draw a line to corresponding to 100% people
Now, when we represent students whose address is available,70 % of them, we should ensure that these 70%people are also a part of the 100% whose name details are available. This way, we are maximizing the number of people for whom both the name & address is available
If you want to visualize this using the circles we are used to
Similarly, for the remaining 3 details, we try to have the maximum area of overlap.
For the next 3 details, the figure would be:
Thus the number of people for whom all five of Name Address Email Mobile and Age data is available Is 30%
However, there are 10% people with Fax No. also who have not been considered. We will place those people strategically, them so that the overlapped region for 5 lines, becomes maximum as follows.
Now count the regions where 5 lines are overlapping. It is 40% of the total
Answer is 40% of 100000= 40000. Option (c)