Given the background: Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. and the situation: Ben and Sam were two twin brothers. One day Ben was feeling sick so they went to the doctor and they discovered that Ben had hepatitis B. Sam was tested as well, but he was 'healthy as an ox'. Answer the following question: Which brother had a disease that can lead to liver cancer?
Ans: Ben

Given the background: One of the main advantages of adopting a strong foreign currency as sole legal tender is to reduce the transaction costs of trade among countries using the same currency.[13] There are at least two ways to infer this impact from data. The first is the significantly negative effect of exchange rate volatility on trade in most cases, and the second is an association between transaction costs and the need to operate with multiple currencies.[14] Economic integration with the rest of the world becomes easier as a result of lowered transaction costs and stabler prices.[2] Rose (2000) applied the gravity model of trade and provided empirical evidence that countries sharing a common currency engage in significantly increased trade among them, and that the benefits of currency substitution for trade may be large.[15] and the situation: Two countries are considering adopting the same currency. Country A will begin to use the currency of Country B if they agree to make this change. Currently there is a 2 to 1 exchange rate on currency from country A to country B but this changes over time. Also in order to exchange the currency you have to pay a 5% fee on whatever the amount is you would like to exchange. Under the new system there will be no exchange rate and there will no longer be a reason to pay the transaction fee as everyone will have the same currency. Answer the following question: Under the current system, will you have more or less money after exchanging currencies?
Ans: less

Given the background: Once again, a mutation is the change in the DNA or RNA sequence. In multicellular organisms, mutations can be subdivided into germline mutations and somatic mutations. Germline mutations occur in the DNA of sex cells, or gametes, and are therefore potentially very serious. These mutations can be passed to the next generation. If the zygote contains the mutation, every cell in the resulting organism will have that mutation. If the mutation results in a disease phenotype, the mutation causes what is called a hereditary disease. Somatic mutations , which occur in somatic, or body, cells, cannot be passed to the next generation (offspring). Mutations present in a somatic cell of an organism will be present (by DNA replication and mitosis) in all descendants of that cell. If the mutation is present in a gene that is not used in that cell type, the mutation may have no effect. On the other hand, the mutation may lead to a serious medical condition such as cancer. and the situation: Dan studied multicellular organisms that presented mutations. Group A presented gemline mutations, while group B presented somatic mutations. He was fascinated by these organisms. Answer the following question: Which group had fewer organisms having mutations that can be passed to the next generation?
Ans: group B

Given the background: Antifreeze could also be called "antiboil" because it also raises the boiling point of the water in a car radiator. Hot weather combined with a hot engine can easily raise the temperature of the water in the radiator above 100 C, which is the boiling point of pure water. If the water boils, it could cause the engine to overheat and become seriously damaged. However, if antifreeze has been added to the water, the boiling point is much higher. For example a 50 percent antifreeze solution has a boiling point of 129 C. Unless the water gets hotter than this, it won't boil and ruin the engine. and the situation: John was driving through the Mohave desert. He first added antifreeze to the water in his radiator. He noted that in his journal as case A. Unfortunately, after some time he ran out of antifreeze, and couldn't add antifreeze any more. He noted that as case B. Answer the following question: In which case the engine would be cooler, case a or case B?
Ans: case A