Please wait...
1800-212-7858 (Toll Free)
9:00am - 8:00pm IST all days

or

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this toll free number

022-62211530

Mon to Sat - 11 AM to 8 PM

two balls are drawn from an urn containing 2 white 3 red and 4 black balls one by one without replacement. What is the probability that at least one ball is red?

Asked by Pragyashree Jain 17th March 2015, 4:54 PM
Answered by Expert
Answer:
L e t space A space b e space t h e space e v e n t space o f space g e t t i n g space a space n o n minus r e d space b a l l space i n space t h e space f i r s t space d r a w space a n d l e t space B space b e space t h e space e v e n t space o f space g e t t i n g space a space n o n minus r e d space b a l l space i n space t h e space s e c o n d space d r a w.  P open parentheses A close parentheses equals P r o b a b i l i t y space o f space g e t t i n g space a space n o n minus r e d space b a l l space i n space t h e space f i r s t space d r a w. rightwards double arrow P open parentheses A close parentheses equals 6 over 9 equals 2 over 3... left parenthesis 1 right parenthesis P open parentheses B close parentheses equals P r o b a b i l i t y space o f space g e t t i n g space a space n o n minus r e d space b a l l space i n space t h e space s e c o n d space d r a w. W h e n space a space n o n minus r e d space b a l l space i s space d r a w n space i n space t h e space f i r s t space d r a w comma space t h e r e space a r e space 5 space n o n minus r e d space b a l l s space a n d space 3 space r e d space b a l l s. T h e r e f o r e comma space f r o m space 5 space n o n minus r e d space b a l l s comma space o n e space b a l l space c a n space b e space s e l e c t e d space i n space C presuperscript 5 subscript 1 space w a y s. T h u s comma space P open parentheses B divided by A close parentheses equals 5 over 8.... left parenthesis 2 right parenthesis  R e q u i r e d space p r o b a b i l i t y equals P r o b a b i l i t y space t h a t space a t l e a s t space o n e space b a l l space i s space r e d space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 1 minus P r o b a b i l i t y space o f space g e t t i n g space n o n minus r e d space b a l l space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 1 minus P open parentheses A space a n d space B close parentheses space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 1 minus P open parentheses A intersection B close parentheses space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 1 minus P open parentheses A close parentheses cross times P open parentheses B divided by A close parentheses space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 1 minus 2 over 3 cross times 5 over 8 space space space space space space space left square bracket f r o m space e q u a t i o n s space left parenthesis 1 right parenthesis space a n d space left parenthesis 2 right parenthesis right square bracket space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 7 over 12
Answered by Expert 19th March 2015, 9:06 AM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Your answer has been posted successfully!

Chat with us on WhatsApp