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: The United States Navy (USN) hoped to use the V-1710 in its rigid airships USS Akron (ZRS-4) and USS Macon (ZRS-5), but both were equipped with German-built Maybach VL-2 engines as the V-1710 was still in testing when the Macon was lost in February 1935 (the Akron having been lost in April 1933). The USAAC purchased its first V-1710 in December 1932. The Great Depression slowed development, and it was not until December 14, 1936 that the engine next flew in the Consolidated XA-11A testbed. The V-1710-C6 successfully completed the USAAC 150 hour Type certificate on April 23, 1937 at , the first engine of any type to do so. The engine was then offered to aircraft manufacturers where it powered the prototype Curtiss XP-37s. All entrants in the new pursuit competition were designed around it, powering the Lockheed P-38, Bell P-39 and Curtiss P-40. When war British Purchasing Commission asked North American Aviation to build the P-40 under license, NAA instead proposed their own improved aircraft design, using the V-1710 in their North American P-51 Mustang.
How many airships did the United States Navy (USN) hope to use the V-1710 in?

Passage: The Dano-Hanseatic War from 1426-1435  was an armed trade conflict between the Danish dominated Kalmar Union  and the German Hanseatic League  led by the Free City of Lübeck. When Danish king Eric opened the Baltic trade routes for Dutch ships and introduced a new toll for all foreign ships passing the Øresund , six Hanseatic cities  declared war, put a naval blockade on Scandinavian harbours and allied with Eric's enemy Henry IV, count of Holstein. Therefore the war was intensively linked with the Dutch-Hanseatic War , the Kalmar War with Holstein  and the Swedish revolt . After years of changing fortune in warfare Rostock and Stralsund signed a separate peace agreement in 1430. Lübeck, Hamburg, Wismar and Lüneburg, however, continued the war and assisted Holstein to conquer Flensburg in 1431. Thereafter they agreed an armistice in 1432 and started peace negotiations. Meanwhile an anti-Danish revolt broke out in Sweden . In 1434 Eric had to agree an armistice with the Swedes, too. In April 1435 he signed the peace of Vordingborg with the Hanseatic League and Holstein, followed by the peace of Stockholm with Sweden a few months later the same year. The Hanseatic cities were excepted from the Sound Dues but they had to accept Dutch competition in the Baltic trade. The Danish Duchy of Schleswig was ceded to the count of Holstein. Sweden's autonomous rights and privileges were extended. These peace agreements weakened Eric's position dramatically, and in 1439 he got dethroned by Danish, Swedish and Norwegian Privy Councils.
Around how many months do these events span?

Passage: Lithuania became part of the Russian Empire after the final partition of the Polish-Lithuanian Commonwealth in 1795. During World War I Lithuania was occupied by Germany and made part of Ober Ost. On February 16, 1918 the Council of Lithuania declared independence from both Germany and Russia. Three weeks later, the Bolsheviks, encumbered with the Russian Civil War, sued for peace with the Central Powers and signed the  Treaty of Brest-Litovsk. They renounced Russian claims to Finland, Estonia, Latvia, Ukraine, Lithuania and Poland. However, the Lithuanians were only allowed minimal autonomy and could not establish de facto independence. That changed when Germany lost the war and signed the Compiègne Armistice on November 11, 1918. Lithuania soon began organizing basic institutions, and established their first government led by Augustinas Voldemaras. On November 13, 1918, the Soviet Russian government renounced the Treaty of Brest-Litovsk, which had assured Lithuania's independence. The Bolshevik Western Army followed retreating German troops maintaining a distance of about 10-15 kilometres  between the two armies. Demoralized Germans often left valuable armaments and other equipment to the Soviets. The Soviets attempted to spread the global proletarian revolution and sought to establish Soviet republics in the region. They saw Baltic states as a barrier or a bridge into Western Europe, where they could join the German and the Hungarian Revolutions. By the end of December 1918, Bolshevik forces reached eastern Lithuania.

Bolshevik forces reached eastern Lithuania how many months after the council of Lithuania declared independence from Russia?