Quandaries
and Queries |
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Name: Alex Who is asking: Student Level of the question: Secondary Question: What is the unit's digit of the following problem? 3 |
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Hi Alex, I can get you started by considering 3
The point to notice here is that the units digit cycles in a cycle of length four, 3,9,7,1,3,9,7,1, … If you continue the table above for 155 rows then, since 155/4 = 38 with a remainder of 3, will see 38 copies of the cycle 3,9,7,1 and then three more rows where the units digits are 3,9 and 7.
Thus the units digit of 3 Penny |