3^302 mod 5 using Fermat's Little TheoremSolution:`3^(302) ("mod "5)`
Fermat's Little Theorem
`a^(p-1)-=1 ("mod "p)` (where `p` is prime, `a` is not divisible by `p`)
Step-1: Identify conditions :`p=5` is prime.
`a=3` is not divisible by `p=5`.
So, Apply the theorem
`3^(5-1)-=1 ("mod "5)`
`3^(4)-=1 ("mod "5)`
Step-2: Reduce the exponent `302``302-:4=75` with a remainder of `2`
i.e., `302=4xx75+2`
Step-3: SimplifyWe have
`3^(4)-=1 ("mod "5)`
Taking power `75` on both sides
`(3^(4))^75-=1^75 ("mod "5)`
`3^((4xx75))-=1 ("mod "5)`
Multiply by `3^2` on both sides
`3^((4xx75))xx3^2-=1xx3^2 ("mod "5)`
`3^((4xx75)+2)-=3^2 ("mod "5)`
`3^(302)-=9 ("mod "5)`
`3^(302)-=4 ("mod "5)`
`:.` The remainder is `4` when you divide `3^(302)` by `5`
This material is intended as a summary. Use your textbook for detail explanation.
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