Of 38 cities, 7 have a lake and 21 have a river running through them. What fraction of these 38 cities have a lake or a river running through them? Show your work. Which expression can be used to find the fraction of cities that have a lake or a river running through them? Select the correct choice and fill in the answer box to complete your choice.

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.