Question

Emily has a folder of colored paper. The folder has 4 yellow color papers, 5 black color papers, 6 white color papers and 5 brown color papers. (Answer in both fraction and decimal)

a. She picks one paper, record its color, puts it back in the folder and draws another paper. What is the probability of taking out a brown paper followed by a yellow paper? _________________

b. Two colored papers are drawn without replacement from the folder. What is the probability that both of the caps are white? __________________

Answer 1

total number of papers = 4 + 5 + 6 +5 = 20

(a) number of brown papers = 5

P(brown) = (number of brown)/(total) = 5/20

and number of yellow paper = 4

P(yellow) = (number of yellow)/(total) = 4/20

Probability of taking out a brown paper followed by a yellow paper = P(Brown)*P(yellow)

= (5/20)*(4/20)

= 1/20 or 0.05

(b) number of white paper = 6

probability of taking first white paper =(number of white paper)/(total)

=6/20

and probability of taking second white paper =(number of white paper-1)/(total-1)

=5/19

combined probability = P(1st)*P(2nd)

= (6/20)*(5/19)

= 3/38 or 0.0789