DogInt

Probability Level 4

Find the number of integral solutions of D + O + G = 0 \text{D}+\text{O}+\text{G}=0 , with D , O , G ≥ − 7 \text{D}, \ \text{O}, \ \text{G} \geq -7 .


The answer is 253.

Sandeep Bhardwaj by Sandeep Bhardwaj , 28, India

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

Vignesh S
Apr 9, 2016

Define d = D + 7 , o = O + 7 , g = G + 7 d=D+7 , o=O+7 , g=G+7 . Now its equivalent to finding the integral solutions of d + o + g = 21 d+o+g=21 . This can be done in ( n + r − 1 r − 1 ) \dbinom{n+r-1}{r-1} , here n = 21 , r = 3 n=21 , r=3 . Therefore answer is ( 23 2 ) = 253 \binom{23}{2} =253

6 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...