Final answer:
The two multiplication problems that yield a product that is a rational number are A - 2 x 3/4 and C - 27 x 1/9.
Step-by-step explanation:
To determine which of the multiplication problems yield a product that is a rational number, we need to understand that a rational number is any number that can be expressed as a fraction, where the numerator and denominator are both integers.
In multiplication, the product of two rational numbers will always be a rational number. Therefore, the two multiplication problems that yield a product that is a rational number are:
A - 2 x 3/4
C - 27 x 1/9