31 items are filed under this topic.
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The largest integer k so that that 3335^k is a divisor of 3336! |
2019-10-29 |
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From Brandon:
Hello my name is Brandon and I having difficulties in solving the following question: Given the number 3336! = 1.2.3.4........................3336 . What's the greater positive integer number k with the condition that 3335expk is a divisor of 3336!
Thanks for your help.
Answered by Penny Nom. |
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Factorials |
2017-07-27 |
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From dinesh:
Is there any shortcut formula for multiply series numbers.
like
1x2x3x4x5.......x100 =?
Answered by Penny Nom. |
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An exercise with factorials |
2016-02-07 |
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From vidhi:
find the value of n: (1-1/2) (2-2/3) (3-3/4)...(15-15/16) = n!/16
Answered by Penny Nom. |
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Factorials |
2014-06-06 |
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From penny:
What is factorial? For eg. Like 2!, 3! 4! Etc.
Answered by Penny Nom. |
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(1-1/2)(2-2/3)(3-3/4)...(15-15/16)=n!/16 |
2011-02-15 |
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From Fiona:
Could you help me find the value of n: (1-1/2)(2-2/3)(3-3/4)...(15-15/16)=n!/16
Answered by Penny Nom. |
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Factorials |
2010-03-23 |
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From Leah:
When should you use factorials?
Answered by Robert Dawson. |
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The tens digit of 0! + 1! + 2! + 3! + ... + 2000! |
2009-12-21 |
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From Alicia:
What is the tens digit of 0! + 1! + 2! + 3! + ... + 2000!?
Answered by Robert Dawson and Penny Nom. |
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The last non cero digit of a factorial |
2009-06-12 |
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From Wilson:
How can I find the last non cero digit from a factorial calculation of a big number.
For example 10! = 3628800, the last non cero digit is 8.
What is the last non cero digit of 10! ??
Answered by Robert Dawson. |
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The sequence 2n! - 1 |
2009-02-01 |
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From Penny:
I am trying to help my son with this problem. Find the first five terms of the sequence that can be written from the formula A= 2n !-1.
Answered by Penny Nom. |
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The tens digit of 0! + 1! + 2! + 3! + 4! .............+9999! + 10000! |
2009-01-23 |
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From Kaylyn:
determine the tens digit for the expression:
0! + 1! + 2! + 3! + 4! .............+9999! + 10000!
Answered by Robert Dawson and Penny Nom. |
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n choose r equals n-1 choose r plus n-1 choose r - 1 |
2008-07-14 |
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From fae:
Prove that
( n ) = ( n – 1) + ( n - 1 )
( r ) ( r ) (r-1)
NOTE: the ( ) should be one for n taken r and so on. but there is no one big ( ) that will cater two lines
Answered by Janice Cotcher. |
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Sum of factorials |
2008-01-26 |
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From Emily:
What is the tens digit in the sum 7! + 8! + 9! ... + 2006!
Answered by Stephen La Rocque. |
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Finding the last non-zero digits of large factorials |
2007-10-04 |
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From Mukesh:
i have to find last five non zero digits of integer which can be very large (
upto 10^12) . i can find last non zero digit of of any factorial. Now my problem is that
i have to find last five non zero digit of factorial and also i want to general method for
last K non zero digits of factorial n. For example 10!=3628800 so last non zero digit is 8 ,last two
non zero digit is 88 .....and last five non zero digit is 36288.
Answered by Victoria West. |
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Factorial fraction |
2007-08-03 |
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From Sekhoane:
Expand completely: (N-2)!/N!(9N-1)!
Answered by Stephen La Rocque. |
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Combinations |
2007-05-09 |
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From Michael:
Show that 5 X C(n,5) = n X C(n-1,4)
Answered by Stephen La Rocque. |
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Probability of getting an A |
2007-05-09 |
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From Christine:
In a class of 15 people, exactly 3 got an A. If 2
people are randomly chosen from this class, what is the probability that
at least one of these 2 got an A?
Answered by Paul Betts. |
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n-1/(n+1)! + n+1/n! |
2007-03-18 |
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From Cody:
How do you go about simplifying something like this;
n-1/(n+1)! + n+1/n!?
Answered by Steve La Rocque and Claude Tardif. |
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How to find the odds for a lottery jackpot |
2006-04-12 |
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From Harvey:
Is it best to use factorials to calculate the odds of winning a lottery, such as the MegaMillions that is popular in the US, or is there a better way?
Answered by Stephen La Rocque. |
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Prove that p^n >= (p!)/(p-n)! |
2006-02-02 |
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From Rhydian:
PROVE:
pn >= (p!)/(p-n)!
Answered by Penny Nom. |
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Four people are in a race |
2006-01-26 |
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From Tammy:
If 4 people are in a race, how many different placements, i.e., 1st, 2nd, 3rd, 4th, can there be and what is the equation?
Answered by Penny Nom. |
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112! |
2004-05-28 |
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From Beatriz:
1) A bus driver collects identical sets of 5 coins from each passenger. If the totoal colledted was $21.83, how many pennies did the driver get??
2) How many terminal zero in the base 10 expression of 112! (factional) N! means N(N-1)(N-2) .....(2) (1).
Answered by Penny Nom. |
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n! > n^2 |
2004-03-30 |
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From Jose:
How can you prove by mathematical induction that:
n! > n2.
Answered by Penny Nom. |
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When is 1! + 2! + 3! + ... + x! a square? |
2002-08-19 |
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From Sarathy:
Solve : 1! + 2! + 3! + ... + x! = y 2 How do i find the solutions ?
Answered by Claude tardif. |
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Why is 0! = 1? |
2001-01-30 |
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From Diane:
Every math book always claims that 1!=1 and 0!=1 are givens, and that we should just memorize it. i understand the 1! part, but where is the basis for claiming that 0!=1????
Answered by Walter Whiteley. |
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Four crayons |
2001-01-10 |
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From Neyra Espinoza:
You have four crayons (red, blue, yellow, green). If you line them up, how many different combinations can you get?
Answered by Patrick Maidorn. |
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n! = 42(n-2)! |
2000-07-21 |
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From Damon Bailey:
Solve n! = 42(n-2)!
Answered by Paul Betts. |
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10,000! |
2000-07-21 |
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From Lauren:
Hi I was just wondering if you could tell me how many zeros are in 100,000! (factorial.)
Answered by Denis Hanson. |
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Six digit numbers using 1,2,5,6,7, and 9 |
2000-03-20 |
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From Rachel:
How many different six-digit numbers can you make using the digits 1,2,5,6,7, and 9? How many of these six digit numbers are divisible by six?
Answered by Claude Tardif and Denis Hanson. |
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0! + 1! + 2! + 3! + ... + 2000! |
1999-10-21 |
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From Melissa:
My name is melissa. I am a 9th grade student I am having trouble finding out how to do this: What is the tens digit of 0! + 1! + 2! + 3! + ... + 2000! I know how to find these, but my calculator cant go any higher than 69! Is there any way i can do this problem?
Answered by Penny Nom. |
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0! |
1997-03-02 |
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From Donna D. Hall:
I am looking for a quick and easy explanation as to why 0! is 1.
Answered by Walter Whiteley and Denis Hanson. |
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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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