remainder of X

Calculus Level 2
  • There is a number X:
  • X=1234...201620172018
  • (123456 to 2018)
  • Now, what is the remainder of X if X is divided by 9?


The answer is 3.

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.

1 solution

Greatful Greatful
Apr 27, 2018
  • As the special formula of multiple of 9 are
  • 9x1 = 9,9 = 9
  • 9x2 = 18,1+8 =9
  • 9x3 = 27,2+7 =9
  • 9x4 = 36,3+6 = 9
  • ...
  • s e p a r a t i o n separation l i n e line
  • We only need to add all numbers in X (1,2,3,4,...,2016,2017,2018) to find the number to be divided by 9
  • ( F i r s t N u m b e r + L a s t N u m b e r ) L a s t N u m b e r 2 \frac{(FirstNumber+LastNumber)*LastNumber}{2}
  • = ( 1 + 2018 ) 2018 2 \frac{(1+2018)*2018}{2}
  • =2037171
  • s e p a r a r t i o n separartion l i n e line
  • Then, we divide it by 9:
  • 2037171/9
  • =226352 3 10 \frac{3}{10}
  • s e p a r a t i o n separation l i n e line
  • Since we are looking for the remainder of X,
  • we do not care about the actual value,
  • and we only care about the fraction formed.
  • Therefore, the remainder is 3 .

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...