15. Viruses are much smaller than bacteria, Some viruses measure 0,0001 mm in
diameter. An artist's diaggam of a virus
shows the diameter as 5 mm. Determine
the scale factor used,

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.

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Is the figure congruent? yes or no?