CAT
Exam
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find the remainder when 51^203 is divided by 7
Read Solution (Total 4)
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- 51%7=2
(2)^203/7=4*(2^3)^67/7
=4*(7+1)^67/7
=4*(1)^67/7
=4*1 =4 rem(ans) - 10 years agoHelpfull: Yes(4) No(0)
- 51^203/7 = (7*7+2)^203/7 = 2^203/7
= (2^3)^67 * 2^2 / 7
= (8)^67 * 4 / 7
= (7*1+1)^67 * 4 /7
= (1)^67 * 4 / 7
= 4/7
= 4 - 10 years agoHelpfull: Yes(2) No(0)
- ans is 4
remainder will be 4
- 10 years agoHelpfull: Yes(0) No(0)
- 51^203, the power 203 is completely divide by 7(prime)
wkt, Fermat little theorem:
If P is a prime number then (a^p−1/p)=1 or (a^p/p)=a;
(51^7)^29/7=(51)^29/7=(51^7)^4*51/7=(51^5)/7=(2^5)/7=32/7=4;
- 10 years agoHelpfull: Yes(0) No(0)
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