The city has numerous neighborhoods consisting of vacant properties resulting in low inhabited density in those areas, stretching city services and infrastructure. These neighborhoods are concentrated in the northeast and on the city's fringes. A 2009 parcel survey found about a quarter of residential lots in the city to be undeveloped or vacant, and about 10% of the city's housing to be unoccupied. The survey also reported that most (86%) of the city's homes are in good condition with a minority (9%) in fair condition needing only minor repairs.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many of Detroit's residential lots are are underdeveloped?
Ah, so.. a quarter

Northwestern's Evanston campus, where the undergraduate schools, the Graduate School, and the Kellogg School of Management are located, runs north-south from Lincoln Avenue to Clark Street west of Lake Michigan along Sheridan Road. North and South Campuses have noticeably different atmospheres, owing to the predominance of Science and Athletics in the one and Humanities and Arts in the other. North Campus is home to the fraternity quads, the Henry Crown Sports Pavilion and Norris Aquatics Center and other athletic facilities, the Technological Institute, Dearborn Observatory, and other science-related buildings including Patrick G. and Shirley W. Ryan Hall for Nanofabrication and Molecular Self-Assembly, and the Ford Motor Company Engineering Design Center. South Campus is home to the University's humanities buildings, Pick-Staiger Concert Hall and other music buildings, the Mary and Leigh Block Museum of Art, and the sorority quads. In the 1960s, the University created an additional 84 acres (34.0 ha) by means of a lakefill in Lake Michigan. Among some of the buildings located on these broad new acres are University Library, Norris University Center (the student union), and Pick-Staiger Concert Hall.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"):  Which campus is not home to the fraternity quads?
Ah, so.. unanswerable

A solar balloon is a black balloon that is filled with ordinary air. As sunlight shines on the balloon, the air inside is heated and expands causing an upward buoyancy force, much like an artificially heated hot air balloon. Some solar balloons are large enough for human flight, but usage is generally limited to the toy market as the surface-area to payload-weight ratio is relatively high.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What happens when sunlight shines on a solar balloon?
Ah, so..
the air inside is heated and expands causing an upward buoyancy force