The temperature in potter's kiln dropped 760 degrees in 4 hours. on average, how much did the temperature drop per hour?

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

What is the area of the original rectangle? 8 cm² 20 cm² 25 cm² 40 cm²

Ithink i know it but i want to be sure so can you me out ?