A person is asked to randomly pick two balls from a bag which has 15 yellow & 5 red balls. The probability that the person picks two balls of the same colour is
a) 33/38 b) 23/38
c) 38/43 d) 15/38

• 15C2+5C2/20C2
  =15*7 + 5*4 / 10*19
  =21 + 2 / 2*19
  =23/38
• 11 years agoHelpfull: Yes(30) No(2)
• 15/20*14/19+5/20*4/19=23/38
• 11 years agoHelpfull: Yes(6) No(1)
• if person picks same colour of two balls then he pick one ball from yellow and other one is red so totally pick 2balls from 20 balls the probability is (15c1*5c1)/20c2=15/38
• 11 years agoHelpfull: Yes(3) No(14)