The product between two numbers is the same as the multiplication of those two numbers.
Then, the phrase "The product between 30 and a number j" is the same as to multiply 30 and j.
Additionally, when a number is written to the left of a variable, that means that the number is the coefficient of that variable, which is multiplying it.
Then, the expression that correctly represents the phrase "The product of 30 and a number j" is shown in option c) 30j.
