A sports store had 60 backpacks in stock, some with wheels and some without wheels, before a new shipment of backpacks arrived. The number of wheeled backpacks in the new shipment was twice the number
of wheeled backpacks already in stock, and the number of backpacks without wheels in the new shipment
was five times the number of backpacks without wheels already in stock. After the new shipment arrived, there
were 330 backpacks in the store. Before the new shipment, there were x wheeled backpacks and y
backpacks without wheels. Which of the following equations can be used with x + y = 60 to solve for x and y?

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.