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7.4: Assessment Module 5: Modular Arithmetic

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    Modular Arithmetic

    MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

     

    Determine if the statement is true or false.

    1) 1351  0 (mod 7) 1)
    A) False B) True
    2) 11 4 (mod 7) 2)
    A) False B) True
    3) 66 7 (mod 12) 3)
    A) False B) True

     

    Find the sum.

    4) (6 + 5) (mod 6) 4)
    A) 5 B) 6 C) 11 D) 4
    5) (48 + 48) (mod 50) 5)
    A) 4 B) 46 C) 50 D) 96

     

    Find the sum or product using the requested clock system.

    6) 8 + 10 in 12-hour clock arithmetic 6)
    A) 2 B) 8 C) 6 D) 0
    7) 7 · 16 in 12-hour clock arithmetic 7)
    A) 4 B) 5 C) 16 D) 11
    8) 3 + 221 in 7-day clock arithmetic 8)
    A) 3 B) 5 C) 0 D) 8
    9) 1400 + 1900 in the military 24-hour clock system 9)
    A) 0930 B) 12100 C) 1900 D) 0900
    10) 0930 + 1640 in the military 24-hour clock system 10)
    A) 0310 B) 2610 C) 0210 D) 2570

     

    Decide whether the congruence statement is true or false.

    11) 6  13 (mod 2) 11)
    A) True B) False
    12) 0  26 (mod 7) 12)
    A) True B) False
    13) 19  77 (mod 5) 13)
    A) True B) False
    14) 5  21 (mod 5) 14)
    A) True B) False

     

     

     

     

    1

    15) 3   13 (mod 11)                                                                                                                             15)

    A) True                                                               B) False

     

    Perform the modular arithmetic operation.

    16) (46 + 37)(mod 7) 16)
    A) 6 B) 7 C) 11 D) 5
    17) (130 + 106)(mod 9) 17)
    A) 10 B) 26 C) 2 D) 1
    18) (10 · 7)(mod 6) 18)
    A) 3 B) 6 C) 11 D) 4
    19) [(11 + 7) · (7 + 3)](mod 7) 19)
    A) 4 B) 7 C) 25 D) 5
    20) (49 – 25)(mod 5) 20)
    A) 3 B) 0 C) 120 D) 4
    21) (15 – 53)(mod 4) 21)
    A) 3 B) 2 C) 1 D) 152
    22) [(3 · 7) – 5](mod 4) 22)
    A) 1 B) 3 C) 2 D) 0
    23) [(13 · 3) + 9](mod 8) 23)
    A) 3 B) 7 C) 0 D) 1
    24) [(4 – 9) · 7](mod 5) 24)
    A) 2 B) 0 C) 4 D) 3
    25) [(-5) · 6](mod 7) 25)
    A) -5 B) 5 C) -2 D) 1

     

    Find all positive solutions for the equation.

    26) x  4 (mod 7) 26)
    A) {1, 18, 25, …} B) {4, 11, 18, …} C) {4, 8, 12, …} D) {11, 18, 91, …}
    27) 2x  1 (mod 3) 27)
    A) {2, 6, 10, 14, …} B) {1, 4, 7, 10, …}
    C) {2, 5, 8, 11, …} D) None
    28) 2x  8 (mod 10) 28)
    A) Identity B) {4, 9, 14, 19, 24, 29, …}
    C) {4, 14, 24, …} D) {9, 19, 29, …}
    29) 8x  4 (mod 4) 29)
    A) {4, 8, 12, …} B) {1, 5, 9, …} C) Identity D) {2, 6, 5, …}

     

     

     

    2

    30) 10x  1 (mod 10) 30)
    A) {1, 10, 15, …} B) None C) Identity D) {2, 7, 12, …}
    31) (2 + x)  5 (mod 4) 31)
    A) {4, 6, 8, 10, 12, 14, …} B) {0, 2, 4, 6, 8, 10, …}
    C) {3, 7, 11, 15, 19, 23, …} D) None

     

     

     

     

     

     

     

     

     

     

     


    7.4: Assessment Module 5: Modular Arithmetic is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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