which of these numbers can be classified as both real and rational ?

a) 1/2
b) -1.016879413894
c)square root of 5
d) 0.89089908999

1 answer

all numbers are real

a) , b) and c) are also rational

I can write each as a fraction

e.g. 0.89089908999 = 89089908999/100000000000

c) is real but irrational, (can't write it as a ratio)