Step 1 :We have a total of 13 televisions, out of which 2 are defective and 11 are working.
Step 2 :We are to select 2 televisions randomly and find the probability that both are working.
Step 3 :The total number of ways to select 2 televisions from 13 is given by the combination formula \(C(n, r) = \frac{n!}{r!(n-r)!}\) where n is the total number of items, r is the number of items to choose, and '!' denotes factorial. In this case, n=13 and r=2. This gives us a total of 78 ways.
Step 4 :The number of ways to select 2 working televisions from the 11 that are working is also given by the combination formula. In this case, n=11 and r=2. This gives us a total of 55 ways.
Step 5 :The probability that both televisions work is then given by the ratio of these two quantities, which is \(\frac{55}{78} = 0.705\).
Step 6 :Final Answer: The probability that both televisions work is \(\boxed{0.705}\).