Question 1162571
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(a)  It means that you chose all 3 yam tubers from the set of 15-5 = 10 yam tubers that are not spoilt.


     Therefore, the probability (a) is  P = {{{(10/15)*(9/14)*(8/13)}}} = {{{(2/3)*(9/14)*(8/13)}}} = {{{(3/7)*(8/13)}}} = {{{24/91}}} = 0.2637.         <U>ANSWER</U>




(b)  It means that you chose all 3 yam tubers from the set of 5 yam tubers that are spoilt.


     Therefore, the probability (b) is  P = {{{(5/15)*(4/14)*(3/13)}}} = {{{(1/3)*(2/7)*(3/13)}}} = {{{(2/7)*(1/13)}}} = {{{2/91}}} = 0.0220.      <U>ANSWER</U>




(c)  In this case, the probability is  P = {{{3*(5/15)*(10/14)*(9/13)}}} = {{{(5/7)*(9/13)}}} = {{{45/91}}} 0.4945.      <U>ANSWER</U>




(d)  In this case, the probability is the COMPLEMENT to case (a)  P = 1 - 0.2637 = 0.7363.      <U>ANSWER</U>
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Solved.