Robinmrtha wrote:Let 100 be the number of participants

Then draw the table...
Total Reg and who have paid the full amount = 72
Total full paid x
Total full paid but late registered x - 72

Reg Late Reg Total
Full pay 72 x-72 x

By question late reg and full pay =10 percent of x

So,
x-72= 10 percent of x
Therefore x= 80

Ans D

Morgoth wrote:I think the question is incorrect or at least the last part is incorrect.

The above venn diagram by tohellandback incorrectly calculated on the statement that
"If 10% of the attendees who paid their conference fee in full did
not register at least two weeks in advance"

The full part should be taken as x not the at least 2 weeks part.

Here are my calculations:






Let the total attendes be 100, 72% of the attendees registered at least
two weeks in advance and paid their conference fee in full.

Let people who paid in full be x, 10% of the attendees who paid their conference fee in full did not register at least two weeks in advance

Therefore, 10%x did not register 2 weeks in advance but paid in full.

Hence, we can only find out how many people actually paid in full.

x = 10%x + 72

.9x = 72

x = 80


Please let me know what you guys think about this or is there something that I am completely oblivious about.

Thanks.