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4821x14y is an 8-digit number divisible by 72 |
2014-08-06 |
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RAYA pose la question : if 4821x14y is an 8-digit number divisible by 72. How many values can x and y take? Penny Nom lui répond. |
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A 4 digit number |
2014-04-04 |
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LIM pose la question : "A" is a 4 digit number formed by all the numbers from 1 to 4. When "A" is divided by 9, the remainder is the biggest possible value. What is the biggest value of A? Chris Fisher lui répond. |
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An even multiple of 27 |
2011-02-01 |
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parth pose la question : the 6 digit # 63x904 is an even multiple of 27 what is X Penny Nom lui répond. |
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Powers |
2010-10-20 |
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dylan pose la question : how do you write 20736 in exponential form .same for 1728 and 50625.
is there a formula to figure out how to express large know numbers in exponential form. Penny Nom lui répond. |
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Divisibility rules |
2001-09-07 |
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A student pose la question : Why is it that when you add the digits of a number you can tell what the multiples of that number are. Example: 12131313111,
1+2+1+2+1+3+1+1+1=18,
therefore 12131313111 is divisble by 2, 9, 18, & 3 because those numbers are divisble by 18. Penny Nom lui répond. |
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Divisibility by 9 |
2000-10-24 |
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Kelera pose la question : 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? Penny Nom lui répond. |
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Divisibility by 3 |
2000-03-24 |
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Pat Walsh pose la question : W hy does it work when you add the digits of a number then divid by three to see if the number is divisible by three Penny Nom lui répond. |
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Divisibility by 9 |
1999-02-21 |
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Razzi pose la question : I've been having a hard time trying to solve the following problem and I was wondering if you could help me. For any positive integer a let S(a) be the sum of its digits. Prove that a is divisible by 9 if and only if there exist a positive integer b such that S(a)=S(b)=S(a+b). Chris Fisher and Harley Weston lui répond. |
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