15 items are filed under this topic.
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Divisibility of 3n^5+7n |
2016-12-14 |
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From Parag:
Question from Parag, a student:
if n is a natural number,then 3n^5+7n is divisible by
a)2
b)3
c)5
d)7
i got the answer but still i need a valid alternate approach.
Answered by Penny Nom. |
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4821x14y is an 8-digit number divisible by 72 |
2014-08-06 |
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From RAYA:
if 4821x14y is an 8-digit number divisible by 72. How many values can x and y take?
Answered by Penny Nom. |
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The square of any odd number, decreased by 1, is divisible by 8 |
2012-11-16 |
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From bailey:
Prove that the square of any odd number, decreased by 1, is divisible by 8
Answered by Penny Nom. |
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The difference of the two numbers |
2010-02-15 |
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From Steve:
The difference of the two numbers 'abcdef ' and ' fdebca ' is divisible by 271. prove
that b = d and c = e.
Answered by Claude Tardif. |
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How many combinations of 8614 are divisible by 7? |
2008-01-22 |
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From Rebecca:
How many combinations of 8614 are divisible by 7 equally (with no remainder)?
Answered by Penny Nom. |
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Induction - divisibility |
2007-08-04 |
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From Jerry:
How would you prove that for any positive integer n, the value of the expression 3^(2n+2) - 8n -9 is divisible by 64.
Answered by Chris Fisher and Penny Nom. |
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Divisibility |
2007-05-18 |
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From Ashish:
A number is divisible by 2^n if the last n digits of the number are divisible by 2^n.
Why?
Answered by Penny Nom and Claude Tardif. |
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Divisibility by each of the first ten counting numbers |
2005-10-17 |
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From Simon:
determine smallest positive integer that is divisible by each of the first ten counting numbers
Answered by Penny Nom. |
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A 3 digit number divisible by 7 |
2004-05-03 |
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From A student:
We need to arrange 1,3 and 6 to form a 3 digit number that is divisible by 7.
Answered by Penny Nom. |
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Divisibility by 2 or 5 or both |
2003-10-30 |
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From Abdu:
How many positive integers less than 1,001 are divisible by either 2 or 5 or both?
Answered by Penny Nom. |
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Three consecutive positive intergers |
2003-02-09 |
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From Yew:
Prove that when we multiply any consecutive positive intergers, the result is always divisible by 6.
ex. (7)(8)(9) = 504 = 6 (84)
Answered by Penny Nom. |
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Divisibility of 5 2002 |
2002-08-25 |
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From Simon:
I need to ask you a question if 5 2002 and 3 2002 are divisible by 26.
Answered by Penny Nom. |
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Divisibility by 9 |
2000-10-24 |
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From Kelera:
If the sum of the digits of a number is divisible by 9, then the number itself it divisible by 9. Why is that? How do you explain this?
Answered by Penny Nom. |
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111...1222...2 |
1999-08-11 |
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From Brad Goorman:
Let N = 111...1222...2, where there are 1999 digits of 1 followed by 1999 digits of 2.
Express N as the product of four integers, each of them greater than 1.
Answered by Penny Nom. |
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Divisibility of 2n choose n. |
1996-09-24 |
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From Kathy Doan:
Can you prove that "2n choose n" is not divisible by 3, 5, and 7 for infinitely many n?
Answered by Penny Nom. |
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