Another maths probability question... help please

this time, i'm sure it has somethng to do with independent events ' P(A and B) = P(H) x P(6) ' as well as mutually exclusive events ' P(A OR B) = P(H) + P(6) '

but i don't know how to imply it to the question! please give me explanations on how you got it!

question:

the probability of Nina choosing a choclate bar is 1/3 and of choosing a toffee bar is 1/5
the probability of Zoe choosing a chocolate bar is 1/4 and of choosing a toffee bar is 1/2

calculate the probability of one choosing a chocolate and the other choosing a toffee bar.

the answer is 26/120 but whyy? thank you in advance! your help really appreciated!

Event -1
Probability that Nina choosing a chocolate bar and Zoe choosing a toffee bar = 1/3 * 1/2 = 1/6
Event-2
Probability that Nina choosing a toffee bar and Zoe choosing a chocolate bar = 1/5 * 1/4 = 1/20
In case of event 1 and 2 the probabilities are obtained by using the MULTIPLICATION theorem of Probability as they are independent events.

Since you need the probability of one choosing a chocolate bar and the other choosing a toffee bar
the above events can be considered as possible. Since these two events are mutually exclusive, the ADDITION theorem of Probability is to be used for finding the required probability.

Required probability = 1/6 + 1/20 = 20/120 + 6/120 = 26/120