When is divide by 11, the remainder is
When is divide by 11, the remainder is
Solution
You can find the cyclicity easily (use the calculator if available):
| Power | Division | Quotient + Remainder |
|---|---|---|
remainder | ||
remainder | ||
remainder | ||
remainder | ||
remainder | ||
remainder | ||
remainder |
The cycle repeats every 5 powers: 3, 9, 5, 4, 1.
This means that we can find the general form for every divided by 11.
We know that in this case. Hence, breaking in the general form will allow us to map it to the remainder.
| General Form | Example | Remainder |
|---|---|---|
We need to find where fits in the cycle of (i.e. find the highest multiple of before ):
Since multiples of end in or , we can break down .
(where is a whole number and )
Hence,
From the table, we see the remainder at is
It means that the remainder of is the same as . You can use this pattern-finding approach (cyclicity) for any numbers!
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