Someone can explain this to me well, this can use part 5 as an example, to understand and do it myself

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.

Jo divides a candy bar into eight equal pieces for her children to share she gives three pieces to sam three pieces to leslie and two pieces to margie rose the two month old baby does it doesn't get any what fraction shows how muchw candy each of the four children got. what's the answer to my question

X^2/100+y^2/25=1 the length of the major axis is: a)5 b)10 c)20