Let the number of widgets of type A be \( a \) and type B be \( b \).
From Statement I:
Each unit of A uses 2 machine hours, each unit of B uses 4.
Total machine hours: \( 2a + 4b \leq 80 \) — but no information about values of \( a \) and \( b \).
From Statement II:
Dealer demands at least 10 units of A: \( a \geq 10 \)
Dealer demands at least 15 units of B: \( b \geq 15 \)
Still, we cannot determine the exact value of \( a \).
Using both I and II:
We combine constraints:
\( a \geq 10 \), \( b \geq 15 \) and \( 2a + 4b \leq 80 \)
Substitute \( b = 15 \) (minimum allowed), we get:
\( 2a + 4(15) \leq 80 2a + 60 \leq 80 2a \leq 20 a \leq 10 \)
But also, \( a \geq 10 \). So the only feasible value is:
\[
\boxed{a = 10}
\]