Tell me the mixed numbers for 16/3

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.

If each bricks costs and he can only buy one brick how much will it cost him to get the material to put around the outside of his garden?