<h2><center>Welcome to the Mathematics × Programming Competition #4 </center></h2>

<h2><center>31/7/2017 UTC 14:00 - 7/8/2017 UTC 14:00</center></h2>

<center>https://steemitimages.com/0x0/https://www.cmu.edu/news/stories/archives/2014/april/images/putnam_400x246.jpg.jpg</center>

<center><h6>*For Chinese version please scroll to the bottom. 中文版請見文末。*</h6></center>

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<center><h2>Question</h2></center>

The following map shows the location of three cities A, B and C. The black lines represent roads. Ken wants to travel from A to C, subject to the following rules:-
- In each move, he travels from one junction to another junction via the roads.
- Throughout the whole journey, he only moves towards the North or the East, but not any other directions.
- He needs to pass through B.

<center>https://steemitimages.com/DQmT2bLGP6sP4MycirpYhrG5PpaSaETEdPJbjyg7hsvaY5v/1.png</center>

How many ways are there for Ken to complete his journey?

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<h2><center>Answer submission</center></h2>

Please submit your answer through this <a href="https://goo.gl/forms/OXj1Bafe4QOU2c3p2">link</a>.

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<h2><center>Rules</center></h2>

- This competition will last for 7 days. After that, no more submission will be accepted.
- Participants who submit the answer as a comment below this post will be **disqualified**.
- Participants can submit an unlimited number of solutions, however only the latest answer will be considered.
- You have to upvote this post in order to be eligible for the competition.

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<h2><center>Prizes</center></h2>

- Prize pool balance carried forward = 5.409 SBD
- SBD payout of this post will be added to the prize pool.
- The **first 3 participants** plus **5 randomly chosen participants** who gave the correct numerical answer will share the prize pool equally. Thanks to @steemstem who kindly sponsored this competition, the **first, second and third** participants who gave the correct numerical answer will get additional **7.5, 5 and 2.5 Steem** respectively!
- Those who **resteemed** this post will have 400% higher chance to win in the lucky draw!
- If not all prizes are given out, they will be accumulated for the next competition.
- @kenchung reserves all the rights to disqualify any suspected cheating players and to decide the distribution of prizes among the winner(s).

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<center>https://steemitimages.com/0x0/https://steemitimages.com/DQmY2jUCgfijKRkYnpsENa1jpv6VFwWe8Ts88cYKcQjiLcp/image.png</center>


The steemSTEM project (@steemstem) is a community-supported project aiming to increase the quality and the visibility of STEM (STEM is the acronym for Science, Technology, Engineering and Mathematics) articles on Steemit. Please support steemSTEM by following @steemstem, joining the <a href ="https://steemit.chat/channel/steemSTEM">chat channel</a> and following the <a href="https://streemian.com/profile/curationtrail/trailing/564">curation trail on Streemian</a>! In order to further promote the use of the chat channel, I will stop announcing the time of next competition via a post. Instead I will announce the time in advance in the chat channel! 

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<h2><center>歡迎參加數學 × 程式編寫比賽 (第四回) </center></h2>

<h2><center>31/7/2017 UTC 14:00 - 7/8/2017 UTC 14:00</center></h2>

<center>https://steemitimages.com/0x0/https://www.cmu.edu/news/stories/archives/2014/april/images/putnam_400x246.jpg.jpg</center>

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<center><h2>問題</h2></center>

以下地圖顯示了三個城市A，B和C的位置，其中的黑線代表道路。 Ken希望從A步行到C，但須遵守以下規則：



- 他在道路上從一個交叉路口行走到另一個交界處時視為一個行動。



- 整個旅程中，他只會向北或東方移動。



- 他需要通過B。



<center>https://steemitimages.com/DQmT2bLGP6sP4MycirpYhrG5PpaSaETEdPJbjyg7hsvaY5v/1.png</center>


問Ken有多少個不同的方法完成這次旅程？

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<h2><center>答案提交</center></h2>

請經<a href="https://goo.gl/forms/OXj1Bafe4QOU2c3p2">此連結</a>提交答案。

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<h2><center>規則</center></h2>

- 此比賽為時7天，其後將不會再接受新答案。
- 嚴禁在回覆公開答案，否則將被取消資格。
- 參加者可以重覆提交答案，但比賽終結時只會考慮最後提交的答案。
- 你必須upvote此帖方能參加比賽。

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<h2><center>獎品</center></h2>

- 累積獎池現為 5.409 SBD。
- 此帖文的 SBD 金額將會加入獎池。
- 首三名以及另外五名隨機抽出並給出正確數字答案的參賽者將平分獎池。
- 另外感謝 @steemstem 的贊助，首三名給出正確數字答案的參賽者將獲得額外的 7.5, 5 及2.5 Steem!
- Resteem此帖文者將有額外400％的得獎機會！
- 若有獎金未被發放，將累積至下一次比賽的獎池。
- 本人保留一切最終權利，包括但不限於取消任何疑似作弊者的資格並決定獲獎者的獎勵分配。

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<center>https://steemitimages.com/0x0/https://steemitimages.com/DQmY2jUCgfijKRkYnpsENa1jpv6VFwWe8Ts88cYKcQjiLcp/image.png</center>


steemSTEM（@steemstem）是一個由steemit社群支持的項目，旨在宣傳STEM（STEM是科學，技術，工程和數學的首字母縮略詞）。 請通過以下方式來支持steemSTEM：追蹤@steemSTEM，加入<a href ="https://steemit.chat/channel/steemSTEM">聊天頻道</a>和加入<a href ="https://streemian.com/profile/curationtrail/trailing/564">Streemian</a>！為了進一步推廣聊天頻道的使用，我將不再透過發文來宣布下一場比賽的時間，我會在聊天頻道中提前公佈比賽時間！