1992 AIME Problems/Problem 6
Problem
For how many pairs of consecutive integers in is no carrying required when the two integers are added?
Solution
Consider what carrying means: If carrying is needed to add two numbers with digits and , then or or . 6. Consider . has no carry if . This gives possible solutions.
With , there obviously must be a carry. Consider . have no carry. This gives possible solutions. Considering , have no carry. Thus, the solution is .
1992 AIME (Problems • Answer Key • Resources) | ||
Preceded by Problem 5 |
Followed by Problem 7 | |
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