D. 4/5. Just have to figure out what is left. so 5/5-1/5=4/5
The first working out is correct, z = 3
Yes, it will always be a rational number. I'll expound on this by defining what a rational number is. It is any number that can be expressed as a fraction. Otherwise, it is called an irrational number with a non-terminating decimal expansion. So, although 1/3 has a non-terminating decimal expansion because it is equal to 0.33333333...., it is still a rational number because it can be expressed into a fraction.
I think the greatest common factor is 4
