In fact 5 2/3 means 5+2/3 for this. So,5+2/3 = 17/3 = 5.6
For first question, if "numbers" are also include rational numbers, you can write any rational number according to this interval. For example, 5.7 , 5.75, 5.9
But the second one, the interval that is shown us has the same value 5.6 and 5.6. So you cannot find a number which should bigger 5.6 and smaller 5.6 . It seems impossible I mean.
