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Printimc
prealgebra intermediate
Problem
Star lists the whole numbers through once. Emilio copies Star's numbers, replacing each occurrence of the digit by the digit . Star adds her numbers and Emilio adds his numbers. How much larger is Star's sum than Emilio's?
(A)
(B)
(C)
(D)
Solution
For every tens digit 2, we subtract 10, and for every units digit 2, we subtract 1. Because 2 appears 10 times as a tens digit and 2 appears 3 times as a units digit, the answer is
Final answer
D