A prime factor is a number that goes into another number evenly. With the numbers 3, 5, and 7, we are looking for numbers that are divisible by all three of these numbers. To find the numbers, we have to multiply 3, 5, and 7 together to get 105. This is the least common number that all three are divisible by. Next, we add 105 to each 105, to get the remaining four numbers. So the answer is, 105, 210, 315, 420, and 525.
