Answer: B) 4/55
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Work Shown:
Define the events
A = she picks jeans
B = she picks a sweatshirt
P(A) = (# of jeans)/(# of skirts or pants)
P(A) = 4/(3+1+2+4)
P(A) = 4/10
P(A) = 2/5
P(B) = (# of sweatshirts)/(# of shirts, sweatshirts or sweaters)
P(B) = 2/(3+5+2+1)
P(B) = 2/11
P(A and B) = probability she picks jeans and sweatshirt
P(A and B) = P(A)*P(B) ... works because A and B are independent
P(A and B) = (2/5)*(2/11)
P(A and B) = (2*2)/(5*11)
P(A and B) = 4/55