Step-by-step explanation:
There are a total of 4 + 1 + 9 + 6 = 20 cookies. So the probabilities of each type for a random cookie are:
P(oatmeal raisin) = 4/20 = 1/5
P(sugar) = 1/20
P(chocolate chip) = 9/20
P(peanut butter) = 6/20 = 3/10
1.666666666666667%
3.00/1.80
1.666666666666667 as a fraction is 5/3