Input: Article: The boroughs are composed by hundreds of colonias or neighborhoods, which have no jurisdictional autonomy or representation. The Historic Center is the oldest part of the city (along with some other, formerly separate colonial towns such as Coyoacán and San Ángel), some of the buildings dating back to the 16th century. Other well-known central neighborhoods include Condesa, known for its Art Deco architecture and its restaurant scene; Colonia Roma, a beaux arts neighborhood and artistic and culinary hot-spot, the Zona Rosa, formerly the center of nightlife and restaurants, now reborn as the center of the LGBT and Korean-Mexican communities; and Tepito and La Lagunilla, known for their local working-class foklore and large flea markets. Santa María la Ribera and San Rafael are the latest neighborhoods of magnificent Porfiriato architecture seeing the first signs of gentrification.

Now answer this question: What is the oldest part of the city?

Output: The Historic Center


Article: Film speed is used in the exposure equations to find the appropriate exposure parameters. Four variables are available to the photographer to obtain the desired effect: lighting, film speed, f-number (aperture size), and shutter speed (exposure time). The equation may be expressed as ratios, or, by taking the logarithm (base 2) of both sides, by addition, using the APEX system, in which every increment of 1 is a doubling of exposure; this increment is commonly known as a "stop". The effective f-number is proportional to the ratio between the lens focal length and aperture diameter, the diameter itself being proportional to the square root of the aperture area. Thus, a lens set to f/1.4 allows twice as much light to strike the focal plane as a lens set to f/2. Therefore, each f-number factor of the square root of two (approximately 1.4) is also a stop, so lenses are typically marked in that progression: f/1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, etc.

Question: What is the effective f-number proportional to?
Ans: the ratio between the lens focal length and aperture diameter


Here is a question about this article: The trophy comes in three parts - the cup itself, plus a lid and a base. There have been two designs of trophy in use, but five physical trophies have been presented. The original trophy, known as the "little tin idol", was 18 inches high and made by Martin, Hall & Co. It was stolen in 1895 and never recovered, and so was replaced by an exact replica, used until 1910. The FA decided to change the design after the 1909 winners, Manchester United, made their own replica, leading the FA to realise they did not own the copyright. This new, larger design was by Messers Fattorini and Sons, and was used from 1911. In order to preserve this original, from 1992 it was replaced by an exact replica, although this had to be replaced after just over two decades, after showing wear and tear from being handled more than in previous eras. This third replica, first used in 2014, was built heavier to withstand the increased handling. Of the four surviving trophies, only the 1895 replica has entered private ownership.
What is the answer to this question: How many parts does the trophy come in? 
****
So... The trophy comes in three parts


The problem: Answer a question about this article:
Initially Eisenhower planned on serving only one term, but as with other decisions, he maintained a position of maximum flexibility in case leading Republicans wanted him to run again. During his recovery from a heart attack late in 1955, he huddled with his closest advisors to evaluate the GOP's potential candidates; the group, in addition to his doctor, concluded a second term was well advised, and he announced in February 1956 he would run again. Eisenhower was publicly noncommittal about Nixon's repeating as the Vice President on his ticket; the question was an especially important one in light of his heart condition. He personally favored Robert B. Anderson, a Democrat, who rejected his offer; Eisenhower then resolved to leave the matter in the hands of the party. In 1956, Eisenhower faced Adlai Stevenson again and won by an even larger landslide, with 457 of 531 electoral votes and 57.6% of the popular vote. The level of campaigning was curtailed out of health considerations.
Who did Eisenhower want as his 1956 running mate?
****
The answer: Robert B. Anderson


Problem: Please answer a question about the following article about Alloy:
When the alloy cools and solidifies (crystallizes), its mechanical properties will often be quite different from those of its individual constituents. A metal that is normally very soft and malleable, such as aluminium, can be altered by alloying it with another soft metal, like copper. Although both metals are very soft and ductile, the resulting aluminium alloy will be much harder and stronger. Adding a small amount of non-metallic carbon to iron produces an alloy called steel. Due to its very-high strength and toughness (which is much higher than pure iron), and its ability to be greatly altered by heat treatment, steel is one of the most common alloys in modern use. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel.
What is superior to pure iron?
A: steel


Question: Read this and answer the question

The mandolin has been used occasionally in rock music, first appearing in the psychedelic era of the late 1960s. Levon Helm of The Band occasionally moved from his drum kit to play mandolin, most notably on Rag Mama Rag, Rockin' Chair, and Evangeline. Ian Anderson of Jethro Tull played mandolin on Fat Man, from their second album, Stand Up, and also occasionally on later releases. Rod Stewart's 1971 No. 1 hit Maggie May features a significant mandolin riff. David Grisman played mandolin on two Grateful Dead songs on the American Beauty album, Friend of the Devil and Ripple, which became instant favorites among amateur pickers at jam sessions and campground gatherings. John Paul Jones and Jimmy Page both played mandolin on Led Zeppelin songs. The popular alt rock group Imagine Dragons feature the mandolin on a few of their songs, most prominently being It's Time. Dash Crofts of the soft rock duo Seals and Crofts extensively used mandolin in their repertoire during the 1970s. Styx released the song Boat on the River in 1980, which featured Tommy Shaw on vocals and mandolin. The song didn't chart in the United States but was popular in much of Europe and the Philippines.

Tommy Shaw sang and played the mandolin in which Styx song?
Answer:
Boat on the River