Mary and Tom park their cars in an empty parking lot with n>=2 consecutive parking spaces (ie, n spaces in a row, where only one car fits in each space). Mary and Tom pick parking spaces at random, of course, they must each choose a different
space. (All pairs of distinct parking spaces are equally likely.) What is the probability that there is at most one empty parking
space between them?

Astudent is determining the influence of different types of food on the growth rate of spiders. she feeds one group of spiders two caterpillars twice a week. the other group received similarly-sized beetles twice a week. she records the amount of time required for individuals to reach sexual maturity. her hypothesis is that the spiders feeding on caterpillars will have a faster growth rate because caterpillars have a higher protein content compared to beetles. in this experiment, what is the dependent variable? spiders assigned to different feeding groups. time required to reach sexual maturity number of prey items fed twice a week. growth rates of each group.