1986 AJHSME Problems/Problem 8
Problem
In the product shown, is a digit. The value of is
Solution
Note that in any multiplication problem, the only 2 digits that will influence the last digit of the number will be the last digits of each number being multiplied.
So, has a units digit of , so is either or . If , then the product is , which is clearly too small, so
See Also
1986 AJHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 7 |
Followed by Problem 9 | |
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All AJHSME/AMC 8 Problems and Solutions |
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