For how many integral values of n are the numbers 2n, 3n and 10 - n the lengths of the sides of an obtuse triangle? ∵ a correct answer + a good explanation will guarantee you a :)
(This is from AMC 10 so if you answer it, Congrats! Ur rlly smart and everyone knows it :)

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.