The temperature of dry ice is -78.5° C. Which is colder, dry ice or liquid nitrogen?

Which of the following questions is a statistical question? (2 points) how many professional sport leagues are there? where do the professional sport leagues play? how many hours of professional training took place over the weekend? how many hours do you spend each week training for a sports league?

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.