Question

Which number produces a rational number when multiplied by 0.5

Answer 1

B.
Rational is defined as being able to write it as a fraction. 2.22/ 2 = 1.11 which is 1 11/100

Answer 2

A rational number can be written in form form a/b where a and b are integers and b≠0

remember that a rational number times an irrational number=irrational

irrational numbers can't be in a/b form

so

A. pi doesn't work, that's irrational
B. this works, we can say 2.22=222/100, when multplied by 0.5, we get 111/100 which is still rational
C. nope
D. we can write this as 2000/999 so it is rational, when multiplied by 0.5, we get 1000/999 which is still rational


answers are B and D