Im not sure how to do this

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

Candy lives in the center of town. her friend darlene lives 28 miles to the east and her friend dana lives 21 miles north. approximately how far do dana and darline live apart ?

The anwser cause i do not understand just plez