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.
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Question: Passage: Hoping to rebound from their divisional road loss to the Packers, the Vikings' Week 11 opponent was the Oakland Raiders, who had former Vikings quarterback Daunte Culpepper under center. After a 79-yard pass from wide receiver Sidney Rice to Visanthe Shiancoe on the first play from scrimmage, the Vikings scored on the very next play on a 10-yard run from Chester Taylor. This was followed by a safety when Culpepper was penalized for intentional grounding in his own endzone. Two plays after the ensuing free kick, the Vikings fumbled the ball just inside Oakland territory, allowing the Raiders to set up a 42-yard field goal for Sebastian Janikowski. On the next drive, the Vikings restored their nine-point lead as kicker Ryan Longwell hit a 30-yard field goal on the first play of the second quarter. A short Oakland drive culminating in 10-yard touchdown pass from Culpepper to tight end John Madsen, followed by another Janikowski field goal, saw the Raiders take the lead for the first time. Four plays later, Minnesota regained a six-point lead on a 38-yard touchdown run from Taylor, but field goals of 42 and 49 yards from Janikowski meant the first half ended with the scores level at 19-19. The Vikings recorded the only score of the third quarter on a 38-yard field goal from Longwell, though they did finish the period on the Raiders' 6-yard line, allowing Taylor to run in his third touchdown on the opening play of the fourth quarter, the first time in his career that he scored three touchdowns in one game. A 52-yard field goal from Janikowski narrowed the margin to 7 points with less than three-and-a-half minutes to play, and after forcing the Vikings to punt just inside the two-minute warning, they had one last chance to level the scores. On the first play of the drive, Culpepper threw the ball in the direction of Justin Fargas, who tipped it up, allowing Chad Greenway to come up with an interception; he went to ground with the ball, but inexplicably got up and attempted to advance it, which allowed left tackle Barry Sims to force a fumble, recovered by right guard Paul McQuistan. That enabled the Raiders to extend their drive, but although they managed to get into Vikings territory, a false start penalty meant Culpepper had to attempt a Hail Mary pass on the final play, but it came up short, giving the Vikings a 29-22 win.

Answer: How many field goals did Janikowski kick during the first half?


Question: Passage: Still looking for their first win of the season, the Panthers flew to Cowboys Stadium for a Week 3 Monday night duel with the Dallas Cowboys.  After a scoreless first quarter, Carolina would get the lead in the second quarter with quarterback Jake Delhomme's 25-yard touchdown pass to tight end Dante Rosario.  The Cowboys would take the lead in the third quarter with kicker Nick Folk's 24-yard field goal and running back Tashard Choice's 5-yard touchdown run.  Dallas would get a further grasp on the lead in the fourth quarter with Folk's 19-yard field goal and cornerback Terence Newman returning Delhomme's 7th interception of the season 27 yards for a touchdown (with Choice getting the 2-point conversion run).  The Panthers tried to rally, but the Cowboys' defense would prevent their comeback from happening.

Answer: How long were each of Nick Folk's field goals?


Question: Passage: Salks vaccine was then used in a test called the Francis Field Trial, led by Thomas Francis, Jr., the largest medical experiment in history at that time. The test began with about 4,000 children at Franklin Sherman Elementary School in McLean, Virginia, and eventually involved 1.8 million children, in 44 states from Maine to California. By the conclusion of the study, roughly 440,000 received one or more injections of the vaccine, about 210,000 children received a placebo, consisting of harmless culture media, and 1.2 million children received no vaccination and served as a control group, who would then be observed to see if any contracted polio. The results of the field trial were announced 12 April 1955 (the tenth anniversary of the death of President Franklin D. Roosevelt, whose Franklin D. Roosevelts paralytic illness was generally believed to have been caused by polio). The Salk vaccine had been 60-70% effective against PV1 (poliovirus type 1), over 90% effective against PV2 and PV3, and 94% effective against the development of bulbar polio. Soon after Salks vaccine was licensed in 1955, childrens vaccination campaigns were launched. In the U.S, following a mass immunization campaign promoted by the March of Dimes, the annual number of polio cases fell from 35,000 in 1953 to 5,600 by 1957. By 1961 only 161 cases were recorded in the United States.

Answer:
By how many polio cases did the prevalence decrease in the four years following 1953?