Question

Can someone help me with this question, please?

Answer 1

The answer to the first question:

`(28/100)/(72/100)=(7)/(18)=(7)/(n)\\ n=18`

The answer to the second question:

`a_(n)=a_(1)+d(n-1)\\d=a_(2)-a_(1)\\\\d=9\\a_(1)=11\\a_(n)=11+9(n-1)`