Question

Simple question I may be over thinking

30. Gift Baskets: The Gift Basket Sore had the following premade gift baskets containing the following combinations in stock.

cookies mugs candy
--------------------------------------
coffee 20 13 10
tea 12 10 12

Choose 1 basket at random. Find the probability that it contains

a. Coffee or candy
b Tea given that it contains mugs
c. Tea and cookies

a. I got 5/7 or .71
b. 10/77 or .13
c. I got 12/77 but I think it's wrong,don't I multiply? - For example:
(20/77)x(12/77)x(10/77)x(12/77) = .0008 or so?

Answer 1

a. Ok
b. 10/23
C. 12/77

Answer 2

(a) total no of coffee we have = 20+13+10=43
total candy = 34
total coffee candy we have are =10
remember or means additon so we will use addition rule here
p(a)+p(b)-p(a intersection b)
so that ; 43/77 + 22/77 - 10/77 = 55/77 or 0.714 Ans

(b) total mugs =23
but mugs containing tea are =10
so by basic probability formula we have favorable events/total sample space.
10/23 or 0.434 Ans.

(c) total cookies 32 and total tea in numbers =34
but we need to find the probability of tea and cookies at the same time
Answer will be 12/77 or 0.1558.

another solution can be that
as it include and word it may refers to multiplication formula with that we have the following solution
formula = p(a).p(b)
total tea= 34
total cookies= 32/77 x 43/77 = 1088/5929 or 0.1836 Ans

well i am not sure about this solution.tell me if someone knows