Estefan brings two bags of sandwiches to a party. One bag contains 6 peanut butter sandwiches, 4 cheese sandwiches and 2 ham sandwiches. The other bag contains 4 peanut butter sandwiches, 2 cheese sandwiches, 4 ham sandwiches and 2 chicken salad sandwiches. If John picks one sandwich from each bag at random, what is the probability both will be peanut butter sandwiches? Express your answer as a common fraction.