Three dice are thrown. what is the probability they will all have the same number?

the probability they will all have the same number means the same number appears on the surface of all of them in the same time

the number may be 1,2,3,4,5, or 6 which are 6 numbers

and all the possible outcomes = 6*6*6 = 206

so 6/216 = 1/36 = 0.0277 = 2.77%