Problem: Child labour:

The Victorian era in particular became notorious for the conditions under which children were employed. Children as young as four were employed in production factories and mines working long hours in dangerous, often fatal, working conditions. In coal mines, children would crawl through tunnels too narrow and low for adults. Children also worked as errand boys, crossing sweepers, shoe blacks, or selling matches, flowers and other cheap goods. Some children undertook work as apprentices to respectable trades, such as building or as domestic servants (there were over 120,000 domestic servants in London in the mid-18th century). Working hours were long: builders worked 64 hours a week in summer and 52 in winter, while domestic servants worked 80 hour weeks.

What was the youngest age of a child working in a factory?
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A: four

Problem: Compact disc:

Due to technical limitations, the original ReWritable CD could be written no faster than 4x speed. High Speed ReWritable CD has a different design, which permits writing at speeds ranging from 4x to 12x. Original CD-RW drives can only write to original ReWritable CDs. High Speed CD-RW drives can typically write to both original ReWritable CDs and High Speed ReWritable CDs. Both types of CD-RW discs can be read in most CD drives. Higher speed CD-RW discs, Ultra Speed (16x to 24x write speed) and Ultra Speed+ (32x write speed) are now available.

Does a High Speed CD-RW drive write faster on ReWriteable CDs or High Speed ReWritable CDs?
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A: unanswerable

Problem: Uranium:

Uranium-238 is the most stable isotope of uranium, with a half-life of about 4.468109 years, roughly the age of the Earth. Uranium-235 has a half-life of about 7.13108 years, and uranium-234 has a half-life of about 2.48105 years. For natural uranium, about 49% of its alpha rays are emitted by each of 238U atom, and also 49% by 234U (since the latter is formed from the former) and about 2.0% of them by the 235U. When the Earth was young, probably about one-fifth of its uranium was uranium-235, but the percentage of 234U was probably much lower than this.

What percentage of the gamma rays of natural uranium are emitted by 234U?
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A: unanswerable

Problem: Southeast Asia:

In the 11th century, a turbulent period occurred in the history of Maritime Southeast Asia. The Indian Chola navy crossed the ocean and attacked the Srivijaya kingdom of Sangrama Vijayatungavarman in Kadaram (Kedah), the capital of the powerful maritime kingdom was sacked and the king was taken captive. Along with Kadaram, Pannai in present-day Sumatra and Malaiyur and the Malayan peninsula were attacked too. Soon after that, the king of Kedah Phra Ong Mahawangsa became the first ruler to abandon the traditional Hindu faith, and converted to Islam with the Sultanate of Kedah established in year 1136. Samudera Pasai converted to Islam in the year 1267, the King of Malacca Parameswara married the princess of Pasai, and the son became the first sultan of Malacca. Soon, Malacca became the center of Islamic study and maritime trade, and other rulers followed suit. Indonesian religious leader and Islamic scholar Hamka (19081981) wrote in 1961: "The development of Islam in Indonesia and Malaya is intimately related to a Chinese Muslim, Admiral Zheng He."

What was the capital of Srivijaya kingdom?
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A:
Sangrama Vijayatungavarman