What is the difference between addition and subtraction?

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

An object in geometry with no width, length or height is a(n):

Write the percent as a fraction or mixed number in simplest form. 0.8%