Tom has nickels, Jon has dimes,and Eliz

has silver dollars.Jon has 7 more coins than Eliz.Tom has 7 fewer coins than ELIZ.Together, the three have $23.55. how many silver dollars does Elis have?
please help me , because i am getting S=20.17, and usualy it should be integer number, thank you.

I agree, I cant make it come out either.