Player A and player B are playing a certain game such that a fair dice is thrown till one of them gets a "6".
Knowing that player A started first,calculate the probability that A wins.
Give your answer up to 2 decimal points.
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.
F i r s t , l e t A 1 d e n o t e t h a t A w i n s f r o m f i r s t t h r o w , B 1 d e n o t e s B w i n s f r o m f i r s t t h r o w l e t A 2 . . . . f r o m s e c o n d t h r o w , B 2 . . . . . f r o m s e c o n d t h r o w , a n d s o o n . . . . . w e k n o w t h a t P ( A 1 ) = 6 1 , P ( A 1 ) = 6 5 , P ( B 1 ) = 6 5 × 6 1 , P ( A 2 ) = ( 6 5 ) 2 × 6 1 . . . ( y o u c a n d r a w a t r e e d i a g r a m ) s o , P ( A w i n s ) = P ( A 1 ) + P ( A 1 B 1 A 2 ) + P ( A 1 B 1 A 2 B 2 A 3 ) + . . . . . . . . . = 6 1 + ( ( 6 5 ) 2 × 6 1 ) + ( ( 6 5 ) 4 × 6 1 ) + ( ( 6 5 ) 6 × 6 1 ) + . . . . . . . = 6 1 × 1 − ( 6 5 ) 2 1 = 0 . 5 4 ( i t ′ s a g e o m e t r i c s e q u e n c e o f i n f i n i t e t e r m s )