On a chilly afternoon in New Jersey, the temperature was 4 degrees Fahrenheit. By nightfall, the temperature dropped 9 degrees Fahrenheit. What is the temperature at nightfall in degrees of Fahrenheit?

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

On a piece of paper graph f(x)=5•(0.4)^x

The half-life of a certain material is 0.004 second. approximately how much of a 20-gram sample will be left after 0.016 second? a. 5 grams b. 16 grams c. 0.32 gram d. 1.25 grams