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Zorluk: OrtaDivisibility Rules and Remainder Theorem

In a digital encryption protocol, a security key is generated based on a master integer NN. When NN is successively divided by 66, 88, and 99, the resulting remainders are 44, 33, and 77, respectively. If NN is the smallest possible positive integer that satisfies these conditions, what is the remainder when NN is divided by 1919?

Cevap: 16

Cevap

16
By applying the rules of successive division and working backwards from a final quotient of 0, the smallest possible integer NN is found to be 358. Dividing 358 by 19 yields a quotient of 18 and a remainder of 16.

Adım Adım Çözüm

1
Set up equations based on the definition of successive division.
N=6q1+4N = 6q_1 + 4, q1=8q2+3q_1 = 8q_2 + 3, and q2=9q3+7q_2 = 9q_3 + 7
Successive division means each division is performed on the quotient of the previous step.
2
Determine the value of the final quotient q3q_3 to minimize NN.
q3=0q_3 = 0
The smallest possible positive initial number NN is obtained when the final successive quotient is zero.
3
Solve for intermediate quotient q2q_2.
q2=9(0)+7=7q_2 = 9(0) + 7 = 7
Substitute q3=0q_3 = 0 into the equation q2=9q3+7q_2 = 9q_3 + 7.
4
Solve for intermediate quotient q1q_1.
q1=8(7)+3=59q_1 = 8(7) + 3 = 59
Substitute q2=7q_2 = 7 into the equation q1=8q2+3q_1 = 8q_2 + 3.
5
Calculate the smallest positive integer NN.
N=6(59)+4=358N = 6(59) + 4 = 358
Substitute q1=59q_1 = 59 into the first equation.
6
Divide NN by 1919 to find the final remainder.
358=19×18+16358 = 19 \times 18 + 16. The remainder is 1616.
The problem asks for the remainder when the resulting NN is divided by 1919.

Anahtar Kavram

Successive Division and Remainder Theorem
Tahmini Süre:1m 30s
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