Find the median of 64,65,67,75,80,85,90,90

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.

Which number completes the inequality? 2/3 < _ < 7/9

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.