Please help im not good at theses

For one history test, keith had to answer 40 questions. of these 40 questions, keith answered 28 of them correctly. what percent did keith get on his history test? round your answer to the nearest tenth if necessary

Find the domain of the following expression: 1/(√x)-2

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?