Welcome to the

1st Mathematics × Programming Competition!

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Question

Difficulty index: 4 / 10

Kenchung has 90 SBD and goes to a store to buy stationery. A pencil costs 9 SBD and a pen costs 10 SBD. How many different possible combinations are there for the stationery he purchased? (Buying nothing at all is not considered as a combination) (He does not have to use all the money) http://www.matthewdeevers.com/wp-content/uploads/2013/08/pens-and-pencils.jpg Photo source: www.matthewdeevers.com ---

Answer submission

- Please submit through this link. - You are not required to show your steps. You can use either a mathematical or programming approach. - This competition will last for 24 hours. After that no more submission would be accepted. ---

Rules

- Participants who submit the answer as a comment below this post will be **disqualified**. - Each participant can only submit once. In case of duplicated submission, the latest answer will be considered. - You have to upvote this post AND the announcement post in order to be eligible for the competition. ---

Prizes

- The final SBD payout of the previous post would be added to the prize pool. The prize pool contains 0 SBD at this moment. - The **first** participant who gave the correct answer will get **75%** of the prize pool. - Other participants who got the correct answers will enter a lucky draw. *Those who resteemed this post will have 400% higher chance to win!* The 5 winners will share **25%** of the prize pool. - If not all prizes are given out, they will be accumulated for the next competition! - @kenchung reserve all the rights to disqualify any suspected cheating players and decide the distribution of prize among the winner(s). ---- Upvote, resteem and follow me at @kenchung if you like my posts!