The difference between set of whole numbers and a set of integers is that:
Whole numbers = {0, 1, 2, 3, 4, 5...}
Integers = {..., -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5...}
If we name contents of the first set as n, in the second set you can have 2n-1 numbers (because we count 0 only once in both sets).
Probability of getting the correct answer in the first question is 1/4
probability of getting the correct answer in the second question is 1/4
probability of getting the correct answer in the second question is 1/4 the probability that he gets one question wrong is 3/4
which is 1/4*1/4*1/4*3/4=3/256
for the four questions because he may get the first answer correct and my be the second question wrong, or the the third wrong and the other correct or the first wrong and others correct we should take care of all this by
multiplying 3/256*4=12/256
=0.046875
in three decimal places we have 0.047
Birmingham and Montgomery both have a state sales tax rate of 4 percent and a local tax rate of 6 percent – although the report notes that part of Birmingham lies in Shelby County, meaning the combined rate is only 9 percent in some parts of the city.
