The events are described as:

E₁ = toss first coin (2 outcomes, so n(E₁) = 2.)

E₂ = toss second coin (2 outcomes, so n(E₂) = 2.)

They are independent, since neither toss affects the outcome of the other toss.

So n(E) = n(E₁) × n(E₂) = 2 × 2 = 4

[We could list the outcomes: HH HT TH TT].