A necklace is made by stringing N indi...

What is the units digit of (13)⁴(17)²(29)³ ？（）

A．9
B．7
C．5
D．3
E．1

If a, b, and c are integers, is the number 3 (a+b)-c divisible by 3 ？（）
(1)a+b is divisible by 3.
(2)c is divisible by 3.

A．条件(1)充分，但条件(2)不充分．
B．条件(2)充分，但条件(1)不充分．
C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D．条件(1)充分，条件(2)也充分．
E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．

A necklace is made by stringing N individual beads together in the repeating pattern red bead, green bead, white bead, blue bead, and yellow bead. If the necklace design begins with a red bead and ends with a white bead, then N could equal ？（）

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(1)；
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(1)m is a prime number.
(2)m and n are consecutive integers.

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(1)s-r=5
(2)r and s are not integers.

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i) if a is in S. then -a is in S, and
ii) if each of n and b is in S, then ab is in S. Is -4 in S（）
(1)1 is in S.
(2)2 is in S.

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Ⅰ 2k
Ⅱ 6k
Ⅲ 4k+6

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Ⅱ. The sum of 10 consecutive even integers
Ⅲ. The product of 13 consecutive integers

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(2) is an integer.

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(2)s=4

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(2)By weight the alloy contains 6 parts lead and 5 parts copper

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(2)If the books are counted out by sixes, there will be one book left over.

How many people are directors of both Company K and Company R ？（）
(1)There were 17 directors present at a joint meeting of the directors of Company K and Company R, and no directors were absent,
(2)Company K has 12 directors and Company R has 8 directors.

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(1)u equals 6.
(2)t equals 2.

In a certain group of people, the average (arithmetic mean) weight of the males is 180 pounds and of the females, 120 pounds. What is the average weight of the people in the group ？（）
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(2)The group contains 10 more females than males.

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(1)n² is an integer.
(2) is an integer.

Are there exactly 3 distinct symbols used to create the code words in language Q ？（）
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(2)There are exactly 15 code words in language Q.

3.2□△6
If □ and △ each represent single digits in the decimal above, what digit does □ represent ？（）
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(2)When the decimal is rounded to the nearest hundredth, 3.24 is the result.

If x and y are different prime numbers, each greater than 2, which of the following must be true ？（）
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Ⅱx-y is an even integer.
Ⅲ is not an integer.

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(1)For every prime number p, if p is a divisor of n, then so is p².
(2) is an integer