Classify each number below as a rational number or an irrational number. (a) Is √26 rational or irrational?

Classify each number below as a rational number or an irrational number.
(a) Is √26 rational or irrational?
(b) Is 73.40 rational or irrational?
(c) Is −√16 rational or irrational?
(d) Is −20/14 rational or irrational?
(e) Is 20π rational or irrational?