Abox contains 13 red blocks, 8 orange blocks,9 green blocks,and 10 blue blocks . shelly randomly chooses a block from the box.
what is the probability that the block will not be green ? write answer as decimal

The best definition for 0.5 is C, rational number, real number. 

0.5 is a rational number because it can be expressed as a ratio, a/b, with b not equal to 0 (0.5 = 1/2). 0.5 is a real number because it's a rational number and all rational numbers are real.