What is the product of 3 and 7?

To determine the product of 3 and 7, you multiply the two numbers together. In this case, multiplying 3 times 7 gives you 21, which is the correct answer.

The process of multiplication involves adding a number to itself a certain number of times. For example, 3 times 7 can be thought of as adding 3 together seven times:

3 + 3 + 3 + 3 + 3 + 3 + 3 = 21.

Thus, the product of 3 and 7 is indeed 21, confirming that this option is the correct choice. This basic arithmetic operation is foundational in mathematics and is often one of the first calculations taught to students.