Another "Faulty Odometer" Problem
Number Theory
Level
3
This odometer is missing the digit 3. After a 2 it jumps to 4.
For example: After 22 it shows 24, after 29 it shows 40, after 299 it shows 400.
What is the true reading if this odometer shows 427 ?
The answer is 267.
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1 solution
Decrease each digit greater than 3 by 1. This gives you 326.
Take this number as in base 9 and express it in base 10.
3 x 9^2 + 2 x 9^1 + 6 x 9^0 which gives you 267