How many have two identical digits and one unique digit of the three-digit integers up to 700?

163-lets work with only one group of one to six hundreds, since all groups will have the same as the others. first, we know that there are three ways a group with the first digit of 1 can have exactly two identical digits:1xx11x1x1in other words, there are 9 possible values of x (i.e., not 1) in each scenario and 3 scenarios, so we have 27 possibilities. multiplying this by 6 for the 6 groups of hundreds will give us 162; however, up through 700 means including 700, which has two identical digits, so we add 1 and get 163.