Question 623169
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi, Previously Posted
A box contains blue and green balls in ratio 3:4. 21 balls in the box  
 {{{b/g = 3/4}}}  b = {{{.75g}}} and .75g + g = 21, {{{g = 21/1.75 = 12}}}
 12 green and and 9 blue, total of 21
2 balls are taken one after the other <u>without replacement</u>
P(2 balls are the same color) = P(both Green) + P(both blue) = {{{(12/21)(11/20) + (9/21)(8/20)}}}