How do i do this? i remember her saying something but i don't know what exactly.

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.

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

The graph shows the distance kerri drives on a trip. what is kerri's speed?