A basket contains 6 red, 4blue, 3green and 2 yellow balls. If two balls are picked at random. What is the probability that either both are green or both are yellow?
option
A. 5/21
B. 101/105
C. 4/105
D. 3/35
E. None Of These

• option c
  (3C2+2C2)/15C2=4/105
• 11 years agoHelpfull: Yes(3) No(1)
• P(E)=N(E)/N(S)
  
  N(S)= 15C2(selecting 2 balls from total number of balls)
  = 15!/(15-2)!*2!
  = 105
  probability that either both are green or both are yellow as to be pick
  so, 1.we need to select 2 green balls from 3 green balls(ie 3c2) &
  2.again we need to select 2 yellow balls from 2 yellow balls(ie 2c2)
  
  N(E)=3c2 + 2c2
  = 3 + 1
  = 4
  
  so that P(E)= 4/105
  
• 10 years agoHelpfull: Yes(2) No(0)
• [3c2/15c2]+[2c2/15c2]=3/105+1/105=4/105
• 10 years agoHelpfull: Yes(1) No(0)