Answers to Problem Set 1

1.  9 tall round:3 tall wrinkled:3 dwarf round:1dwarf wrinkled

2.  1 TTRR: 2 TTRr: 2 TtRR: 4 TtRr: 1 TTrr: 2 Ttrr: 1 ttRR: 
2 ttRr: 1ttrr

3.  1/2

4.  1/2 x 1/2 = 1/4

5.  1/4 + 1/4 = 1/2

6.  The probability that the couple will have 2 sons and one 
daughter in any order is 3/8.  Reworded, this question could 
be:  the probability of having a son, a son and a daughter 
(in that order) is 1/2 x 1/2 x1/2 = 1/8.  The probability of 
having a son, a daughter, a son in that order is 1/8, and 
the probability of having a daughter, a son and a son, in 
that order is also 1/8.  So add them all together (mutually 
exclusive events, use the sum rule) and you get 3/8.

7.  1/2

8.  1/128

9.  1/8

10.  1/2 x 1/4 x 1/4 x 1 x 1 = 1/32

11.  not possible 


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