Which account has the highest annual interest rate?

a.
account 1: interest is compounded daily at a rate of 5.25%.
b.
account 2: interest is compounded monthly at a rate of 5.40%.
c.
account 3: interest is compounded quarterly at a rate of 5.50%.
d.
account 4: interest is compounded annually at a rate of 5.55%.

1- 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. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?