Problem: Two groups G and H are called isomorphic if there exist group homomorphisms a: G H and b: H G, such that applying the two functions one after another in each of the two possible orders gives the identity functions of G and H. That is, a(b(h)) = h and b(a(g)) = g for any g in G and h in H. From an abstract point of view, isomorphic groups carry the same information. For example, proving that g g = 1G for some element g of G is equivalent to proving that a(g) a(g) = 1H, because applying a to the first equality yields the second, and applying b to the second gives back the first.
What similar element do isomorphic groups carry?
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Answer: isomorphic groups

Problem: New Haven (local /nu hevn/, noo-HAY-vn), in the U.S. state of Connecticut, is the principal municipality in Greater New Haven, which had a total population of 862,477 in 2010. It is located on New Haven Harbor on the northern shore of the Long Island Sound in New Haven County, Connecticut, which in turn comprises the outer limits of the New York metropolitan area. It is the second-largest city in Connecticut (after Bridgeport), with a population of 129,779 people as of the 2010 United States Census. According to a census of 1 July 2012, by the Census Bureau, the city had a population of 130,741.
In what county is New Haven located in?
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Answer: New Haven County,

Problem: Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers and scientists to tap into the clunky database. When the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley.
At what milestone was the archive made clunky?
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Answer:
unanswerable