Question 999874
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5.) Bella has 7 green beads, 10 yellow beads and 3 white beads in a pouch. Two beads are drawn without replacement from the pouch. What is the probability that both of the beads are yellow?
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7 + 10 + 3 = 20.


The full space of events consists of combinations of  20  things taken  2  at a time;  i.e.  {{{C[20]^2}}}  combinations.

Of them two yellow beads you can choose by  {{{C[10]^2}}} ways.


Hence,  the probability is


{{{C[10]^2}}} : {{{C[20]^2}}} = {{{(10*9)/(1*2)}}} : {{{(20*19)/(1*2)}}} = {{{(10*9)/(20*19)}}} = {{{(9)/38}}} = 0.236842 (approximately).