Let's break down the problem step-by-step to find the probability that the winning ticket belongs to Neil, given that it belongs to his group.
1. Total Tickets Sold:
The total number of tickets sold for the raffle is 2,000.
2. Tickets Bought by Neil:
Neil bought 10 tickets.
3. Tickets Bought by Neil's Group:
Neil and 9 of his friends each bought 10 tickets. Therefore, they collectively bought:
[tex]\[
10 \text{ friends, including Neil} \times 10 \text{ tickets each} = 100 \text{ tickets}
\][/tex]
4. Winning Ticket Belongs to Neil's Group:
It is given that the winning ticket belongs to Neil's group, which has a total of 100 tickets.
5. Probability Calculation:
The probability we are looking for is the likelihood that the ticket belongs to Neil, given that it is among the 100 tickets owned by his group.
Since Neil has 10 tickets out of the 100 in his group, the probability is:
[tex]\[
\frac{\text{Number of tickets Neil bought}}{\text{Total number of tickets in Neil's group}} = \frac{10}{100} = \frac{1}{10}
\][/tex]
Therefore, the correct answer is:
[tex]\[
\boxed{\frac{1}{10}}
\][/tex]
