To determine the fraction of attendees who did not arrive on time, we need to calculate the fraction of attendees who did arrive on time and subtract it from 1.
Let's break down the information given step by step:
2/5 of the attendees were males.
Let's assume the total number of attendees is represented by "x."
The number of male attendees = 2/5 * x.
7/8 of the male attendees arrived on time.
The number of male attendees who arrived on time = 7/8 * (2/5 * x) = 7/20 * x.
9/10 of the female attendees arrived on time.
The number of female attendees = 3/5 * x (since 2/5 were males, the remaining 3/5 must be females).
The number of female attendees who arrived on time = 9/10 * (3/5 * x) = 27/50 * x.
Now, let's calculate the fraction of attendees who arrived on time:
Total number of attendees who arrived on time = number of male attendees who arrived on time + number of female attendees who arrived on time
= 7/20 * x + 27/50 * x
= (7/20 + 27/50) * x
= (35/100 + 54/100) * x
= 89/100 * x
Finally, let's calculate the fraction of attendees who did not arrive on time:
Fraction of attendees who did not arrive on time = 1 - Fraction of attendees who arrived on time
= 1 - 89/100
= 11/100
Therefore, the fraction of attendees who did not arrive on time is 11/100.
The correct answer is (A) 11/100.