Find the largest divisor of 8 7 7 8 that divides ( 1 1 0 5 8 7 7 8 ) .
Notation: ( N M ) = N ! ( M − N ) ! M ! denotes the binomial coefficient .
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
the solution is very simple . the factors of 8778 are 2,3,7,11,19 .after substitution we see that the numerator has 8778 factorial which already contains 8778 . thus the largest divisor of 8778 that divides 8778 factorial is 8778.
Then 1 0 divides ( 2 1 0 ) ?
Log in to reply
ya because there is a 10 factorial in the numerator
Log in to reply
Nope. ( 2 1 0 ) = 4 5 , not divisible by 1 0 .
Log in to reply
@Muhammad Rasel Parvej – thanks to clear my doubt
Problem Loading...
Note Loading...
Set Loading...
Hermite's First Divisibility Property for Binomial Coefficient ( r n ) states, for n , r ≥ 1 ,
g c d ( n , r ) n ∣ ( r n )
Here g c d ( 8 7 7 8 , 1 1 0 5 ) = 1 , so 8 7 7 8 ∣ ( 1 1 0 5 8 7 7 8 ) . As the largest divisor of 8 7 7 8 is 8 7 7 8 itself, the answer is 8 7 7 8 .
This is my argument. But I believe there must be some better argument, even just by using Hermite's First Divisibility Property . I'm still working on that.