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What-is-the-last-2-digits-of-2-613-




Question Number 14564 by tawa tawa last updated on 02/Jun/17
What is the last 2 digits of      2^(613)
Whatisthelast2digitsof2613
Commented by tawa tawa last updated on 02/Jun/17
God bless you sir.
Godblessyousir.
Commented by tawa tawa last updated on 02/Jun/17
But the question is last two digit
Butthequestionislasttwodigit
Commented by Tinkutara last updated on 02/Jun/17
2 ≡ 2 (mod 100)  2^2  ≡ 4 (mod 100)  2^4  ≡ 16 (mod 100)  2^8  ≡ −44 (mod 100)  2^(16)  ≡ 36 (mod 100)  2^(32)  ≡ −4 (mod 100)  2^(64)  ≡ 16 (mod 100)  2^(128)  ≡ −44 (mod 100)  2^(256)  ≡ 36 (mod 100)  2^(512)  ≡ −4 (mod 100)  2^(613)  = 2^(512 + 64 + 32 + 4 + 1)   = (−4)(16)(−4)(16)(2) = 8192  ≡ 92 (mod 100)  Hence last two digits are 92.
22(mod100)224(mod100)2416(mod100)2844(mod100)21636(mod100)2324(mod100)26416(mod100)212844(mod100)225636(mod100)25124(mod100)2613=2512+64+32+4+1=(4)(16)(4)(16)(2)=819292(mod100)Hencelasttwodigitsare92.
Commented by Tinkutara last updated on 02/Jun/17
2 ≡ 2 (mod 1000)  2^2  ≡ 4 (mod 1000)  2^4  ≡ 16 (mod 1000)  2^8  ≡ 256 (mod 1000)  2^(16)  ≡ −464 (mod 1000)  2^(32)  ≡ 296 (mod 1000)  2^(64)  ≡ −384 (mod 1000)  2^(128)  ≡ 456 (mod 1000)  2^(256)  ≡ −64 (mod 1000)  2^(512)  ≡ 96 (mod 1000)  2^(613)  = 2^(512 + 64 + 32 + 4 + 1)   = (96)(−384)(296)(16)(2)  ≡ −808 (mod 1000)  ≡ 192 (mod 1000)  Last 3 digits are 192.
22(mod1000)224(mod1000)2416(mod1000)28256(mod1000)216464(mod1000)232296(mod1000)264384(mod1000)2128456(mod1000)225664(mod1000)251296(mod1000)2613=2512+64+32+4+1=(96)(384)(296)(16)(2)808(mod1000)192(mod1000)Last3digitsare192.
Commented by tawa tawa last updated on 02/Jun/17
i really appreciate sir.
ireallyappreciatesir.
Commented by mrW1 last updated on 02/Jun/17
good working!  pls find the last 3 digits.
goodworking!plsfindthelast3digits.
Commented by Tinkutara last updated on 02/Jun/17
I do not know how to find last 3 digits.  Maybe in that case, mod 1000 is  required. It will be very lengthy and  calculative (use of calculators).
Idonotknowhowtofindlast3digits.Maybeinthatcase,mod1000isrequired.Itwillbeverylengthyandcalculative(useofcalculators).
Commented by RasheedSoomro last updated on 02/Jun/17
e^x cellent!
excellent!
Commented by mrW1 last updated on 02/Jun/17
very good!  please try to solve  Q13724
verygood!pleasetrytosolveQ13724

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