Dinner party limited to 10 guests. 15 friends are democrats, 10 are republican and 1 is independent. the guests are randomly selected. find the probability that
a) all 10 guests are democrats
b) 5 guests are democrat and 5 are republican
c) 1 independent and 9 other people
d) the 1 independent is not invited

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.