Q: This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.
Passage: In 1665, the Mughal Emperor Aurangzeb decided to take action on the Arakanese marauders and launched the Mughal conquest of Chittagong. He also wanted to avenge for his brother Shah Shuja who was killed in exile by the Arakanese king. The Mughal viceroy of Bengal first lured the Portuguese mercenaries in the service of King Sanda Thudhamma guarding the Chittagong region to defect by giving them fiefs. Then the Mughal fleet took Sandwip in late 1665. In January 1666, a Mughal force of 6500 men and 288 boats took Chittagong after a 36-hours' siege. They subsequently took as far south as Ramu. Arakan had lost the Chittagong province which it had held since 1459. Arakan would not recover from the loss of Chittagong, and went into rapid decline. Central authority collapsed in the late 17th century. Sanda Wizaya briefly revived the kingdom. He went to war with Tripura, and raided Sandwip, Prome and Malun. But after his death, Arakan reverted to chaos where king after king was murdered and central authority barely existed. It was easily overrun by the Konbaung armies in 1784-1785.
A:
By 1665, how many years had Arakan held the Chittagong province?