A box contains 2 blue, 1 red balls. We randomly draw one ball then put it back and add two balls of the same color of that ball in the box. We randomly draw again one ball, if it was red then what′s the probability that the first drawn ball was blue?


Question and Answers Forum

All Questions Topic List
Probability and Statistics Questions
Previous in All Question Next in All Question
Previous in Probability and Statistics Next in Probability and Statistics
Question Number 180775 by Acem last updated on 17/Nov/22

$A b o x c o n t a i n s 2 b l u e, 1 r e d b a l l s . W e r a n d o m l y$ $d r a w o n e b a l l t h e n p u t i t b a c k a n d a d d t w o b a l l s$ $o f t h e s a m e c o l o r o f t h a t b a l l i n t h e b o x . W e$ $r a n d o m l y d r a w a g a i n o n e b a l l, i f i t w a s r e d t h e n$ ${w h a t}^{'} s t h e p r o b a b i l i t y t h a t t h e f i r s t d r a w n b a l l$ $w a s b l u e ?$
Commented by som(math1967) last updated on 17/Nov/22

$50 % ?$
Commented by Acem last updated on 17/Nov/22

${I t}^{'} s l e s s t h a n t h a t$
Commented by som(math1967) last updated on 17/Nov/22

$\frac{\frac{2}{3} \times \frac{1}{5}}{\frac{2}{3} \times \frac{1}{5} + \frac{1}{3} \times \frac{3}{5}} = \frac{2}{15} \times \frac{15}{5} = \frac{2}{5}$ $i . e 40 %$
Commented by Acem last updated on 17/Nov/22

$C o r r e c t S i r! T h a n k s!$
Commented by som(math1967) last updated on 17/Nov/22

$I m a d e a m i s t a k e i n t h e c a l c u l a t i o n$
Commented by Acem last updated on 17/Nov/22

$W h a t m a t t e r s i s t h e m e t h o d, a n d y o u r s w a s$ $100 % c o r r e c t! t h a n k y o u v e r y m u c h .$
Commented by SLVR last updated on 18/Nov/22

$G o o d s i r$
Terms of Service
Privacy Policy
Contact: info@tinkutara.com

Question and Answers Forum