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monroe17
Find n(A) of the following set A={101,102,103,104,...,121}
n(A) = number of items in set A So how many elements are in set A?
In other words, how many whole numbers are there from 101 to 121?
good, you got it
You can either count them out, or you can use the trick Last number - First number + 1 = 121 - 101 + 1 = 21 Either way gives you a count of 21.